21 ms·

Displayport: A Better Video Interface

828 points by zdw 3y ago

bee_rider 3y ago
I just like the little retaining clips, and the satisfying little click you hear/feel when plugging them in.
- green-salt 3y ago
  I have a love/hate relationship with them for when the release tab is in a hard to reach area or doesn't release well, but that's usually the cable's fault. Love that tactile sensation of it being properly mated.
- ComputerGuru 3y ago
  It’s a problem when the x16 slot is the bottom-most and the orientation is such that the clicky thing you must depress is on the bottom side of the DP connector when plugged in, and your case has a ledge after the PCI slots so you cannot realistically depress the latch. Of course, no one would realistically encounter a case/GPU/cable combo like that. Right?
  - jacquesm 3y ago
    Hm, my sample for that situation clocks in at about 100% (n=1). Especially the first time I needed to unplug that cable I was thrown for a bit, I ended up taking the whole case off the floor and using a thin screwdriver to depress the release button from the exposed side, that did the trick.
  - NavinF 3y ago
    Your GPU should be in the x16 slot closest to the CPU because it has the most bandwidth. tbh this sounds like a self-inflicted SFF build problem
    - sokoloff 3y ago
      If you have multiple GPUs in a box, you often have to use the bottom slot as well as the close one. (Passing through dedicated GPUs to different VMs is one case that I’ve experienced.)
    - ComputerGuru 3y ago
      > tbh this sounds like a self-inflicted SFF build problem No, the error is in automatically assuming that the GPU should be the one to get the x16 port. This is a tower server; the x16 and x8 ports are for the SAS cards, network cards, and NVMe drives. The GPU takes whatever is left.
deleted 3y ago
[deleted]
BadBadJellyBean 3y ago
I just wish there was only one connector. Either HDMI or DP. I don't care.
- eviks 3y ago
  Why don't you care if it's a worse one?
- jayd16 3y ago
  It'll be the USB-C port.
  - FinnKuhn 3y ago
    and USB-C allows the transmission of displayport over USB-C
    - jsheard 3y ago
      It also allows the transmission of HDMI over USB-C, so you still have two competing standards
      - hadrien01 3y ago
        There's also Thunderbolt over USB-C that does DisplayPort, but it doesn't support all the same versions as DisplayPort over USB-C. And there's also USB 4 but I don't know/understand if it changes anything.
        masklinn 3y ago
        I think the most applicable bit is that USB4 adds tunneling modes, aside from alternate mode. I'm not entirely clear, but from my understanding alternate mode means the physical connection gets switched over, while tunneling means the tunneled data is sent over USB (so the communication on the wire is USB all along, you get nesting).
gaudat 3y ago
I really really hope that my LG has a DisplayPort input. They do offer a monitor that is the same size and I believe the same panel, but the price increase does not really justify it. So sad that I have to bear with the hell of DP/USBc to HDMI converters...
- andelink 3y ago
  You hope? You’re not able to look at the specs before buying?
LoveMortuus 3y ago
I personally prefer HDMI or DVI, I don't like DisplayPort because on the display that I have, when I turn off the display the computer detects it as if I've physically disconnected the display, which then moves all the windows that I had open around and breaks my macros...
- vel0city 3y ago
  That's a failure of the display or your GPU, not necessarily the port. I've got several monitors with DisplayPort on a few different GPUs that don't do this behavior. Its not something inherent with DisplayPort.
- Aaargh20318 3y ago
  Sounds like an OS problem. When I do that it moves all open windows to the remaining display, but when I turn the other display back on it just moves them back. No special software installed for this, just stock macOS Ventura.
  - LoveMortuus 3y ago
    But when I turn off my displays that are on HDMI or DVI or VGA, the computer still detects them like normal, like they're connected, because they are. I don't understand in which case the 'act like it's physically disconnected' behaviour would be more desired than what we had with all the standards before. I have read that some DisplayPort displays do have an option in the settings to disable this behaviour.
    - Aaargh20318 3y ago
      > But when I turn off my displays that are on HDMI or DVI or VGA, the computer still detects them like normal, like they're connected, because they are. But since they’re off, that doesn’t make any sense, now you can’t reach any windows on those monitors. I think the macOS behavior make the most sense, move them so you can access them, but move them back once the display is turned on.
Veliladon 3y ago
HDMI predates DP by 5 years, switching wouldn't enable any specific use case, and that 5 years head start means HDMI has market inertia. Yes we should use it because it's better but the practicality? There's so much gear that's HDMI that would have to be replaced or require new active adaptors. It's so much industry and consumer effort for such a marginal gain.
- lucideer 3y ago
  Forget all the other pros/cons - MST makes it worth any industry & consumer effort alone.
  - hot_gril 3y ago
    How many people use multiple external displays? For the power users who do, there are already good enough solutions.
    - lucideer 3y ago
      I don't have data on this but if my anecdata is anything to go by, power users aren't your typical multi-monitor users...
- patrickthebold 3y ago
  My monitor is fairly old, but it only does 30Hz on the hdmi cable and 60Hz on the display port cable. I'm not sure the exact versions. I think its displayport 1.2 and HDMI < 2. So for me, it was super important to get display port out.
- metaphor 3y ago
  > HDMI predates DP by 5 years... - HDMI v1.0 initial release = 2002-12-09 - DisplayPort v1.0 initial release = 2006-05-01 To be sure, just under 3.5 years; HDMI rolled into v1.3 a month after DisplayPort v1.0 saw the light of day. Agreed on the impact of market inertia.
  - 3y ago
remix2000 3y ago
With HDMI, I have both video and audio traveling over a single cable. That is _extremely_ convenient. DP _theoretically_ supports audio too, but AFAIK that's not widely implemented.
- lucideer 3y ago
  > That is _extremely_ convenient. I'm open to having my mind changed but I have not really experienced this extreme convenience in practice. The vast majority of things I plug a HDMI cable into either don't have speakers or if they do, the speakers are a bad quality afterthought. In actual fact, what has been an extreme inconvenience is the OS thinking I want HDMI audio instead of whatever much higher-quality* alternative output I actually want to direct my audio to. The only time I've ever gotten high-quality audio output over HDMI is via ARC, which says a lot about the need for HDMI audio... * When I say "much higher-quality", I don't mean HDMI is a low-quality audio transport, I mean the HDMI output devices more often than not have inferior audio output to some other bluetooth / 3.5mm jack device I am using.
  - taeric 3y ago
    It was very convenient for me to have my headphones plugged into the monitor. Made it so I could plug a single cable over to my laptop and have basically everything else already done.
    - lucideer 3y ago
      > headphones plugged into the monitor That sounds cool but I've never see a monitor with a jack. Mine all have many USB ports, but not audio. How common are they?
      - yonatan8070 3y ago
        I have a 144Hz 1080p AOC monitor and a secondary generic LG one, both have an audio jack
      - sublinear 3y ago
nfriedly 3y ago
I'm annoyed nvidia for putting the current generation of HDMI on their recent GPUs, but leaving them with an outdated version of DisplayPort. For a long time, my advice to anyone was to always choose DisplayPort whenever it was an option. But now that has to have the caveat of "if you have a new high-end GPU and a fancy high refresh rate monitor, HDMI might actually be better for your situation"
- gjsman-1000 3y ago
  > I'm annoyed nvidia for putting the current generation of HDMI on their recent GPUs, but leaving them with an outdated version of DisplayPort. That was due to unfortunate timing where HDMI had the specifications ready before DisplayPort did.
  - Sweepi 3y ago
    AMD’s RX 7000 support Display port 2.0 and were released 2 months later then Nvidia’s Ada. Afaik DP 2.0 has been finished in 2019(!).
  - Night_Thastus 3y ago
    I thought it was because their G-Sync modules had not been updated to support the new DP? That was what I heard.
- 111111IIIIIII 3y ago
  And only 1 new version HDMI port but 3 old version DP ports. I use a dual display setup but HDR only works on mu displays with HDMI.
  - Strom 3y ago
    The more expensive Gigabyte RTX 3080+ cards had 3x DP 1.4, 2x HDMI 2.1, 1x HDMI 2.0, which was great even if you could only use 4 of them at the same time due to Nvidia limitations. Unfortunately for the 40 series they stopped offering it and now they're the same as stock Nvidia with 3x DP 1.4, 1x HDMI 2.1. Luckily ASUS still offers a bit more with their 4080+ cards - 2x HDMI 2.1, 3x DP 1.4. I personally depend on the 2x HDMI 2.1 to even be able to run my 4K 144Hz monitors at full speed.
wcfields 3y ago
If we lived in a just, and virtuous world we'd all be using cheap coaxial cables with BNC connectors via whatever version of SDI is the highest bit rate.
- mschuster91 3y ago
  SDI can't do any communication between the source and sink. You can do a limited form if you use two SDI cables (one upstream, one downstream) which is what stuff like BlackMagic's bi-directional micro converter does, but IIRC that's only used for talkback to the camera operator and HDMI CEC messages which is how they implement things like their ATEM Mini consoles triggering recording - not for DDC-style format and framerate negotiations. Also, device manufacturers don't do SDI on consumer devices because SDI is by definition unencrypted and uncompressed, so it's at odds with HDCP. [1] https://www.blackmagicdesign.com/products/microconverters https://www.blackmagicdesign.com/products/microconverters
  - ShadowBanThis01 3y ago
    BMD has done some innovative things through their SDI port, specifically enabling camera control with an Arduino-add-on board. Someone finally did what I've wanted to see for years: built a follow-focus unit that controls the focusing motors in the lenses, so you don't have to bolt a ridiculous contraption (and janky focusing-ring adapters) onto a lens to turn its (non-mechanical) focusing ring manually.
    - mschuster91 3y ago
      What I want to see is someone dump the FPGA in these Micro Converters and hack it to add an USB interface. The Micro Converters are all just the same in the interior: SerDes units and clock/redrivers on the I/O ports and an FPGA that additionally has an USB connection which is used to power the converter but could also be used to do other things. That FPGA should be powerful enough to do a lot of interesting things - anything from fooling around with commands (like with the Arduino board) to image manipulation (e.g. a watermark embed).
- 3y ago
mschuster91 3y ago
> in fact, the first time we mentioned eDP over on Hackaday, was when someone reused high-res iPad displays by making a passthrough breakout board with a desktop eDP socket. Yes, with DisplayPort, it’s this easy to reuse laptop and tablet displays – no converter chips, no bulky adapters, at most you will need a backlight driver. I'm a bit confused by the linked project's PCB [1] - if all that's needed is a backlight driver, why all the differential pairs between the microcontroller and the eDP FFC? [1] https://hackaday.io/project/369/gallery#9e4a0fef705befb8030b2eee0dda0825 https://hackaday.io/project/369/gallery#9e4a0fef705befb8030b...
- bpye 3y ago
  The schematics are available [0]. It looks to me like the MCU is doing some sideband control, but the DisplayPort signal itself is passed through unmodified. [0] https://github.com/OSCARAdapter/OSCAR https://github.com/OSCARAdapter/OSCAR
pid-1 3y ago
Sorry if that sounds stupid, but why isn't Ethernet used for this sort of high bw signaling?
- fsh 3y ago
  The bandwidth is much too low.
  - londons_explore 3y ago
    If this were true, then people would be running datacenter networking over HDMI. Data is data - there is no benefit to designing two entirely different transport mechanisms for video vs other data. You could argue that video data has a deadline to meet - but ethernet already has lots of mechanisms for QoS and bandwidth reservations to make sure that someones torrents don't interrupt something latency sensitive. Sure, they aren't widely supported over the internet, but between your PC and your display - they can be engineered to work properly.
    - wmf 3y ago
      25 Gigabit Ethernet costs ~100x more than 32 Gigabit Displayport.
      - aidenn0 3y ago
        Sounds like the real question is why don't people use DP for p2p networking links...
        xienze 3y ago
        There’s nothing magic about DP cables, they’re just typically a short-ish length, which is why they can be high bandwidth and relatively cheap. Once you get to a decent length, the cables get really expensive because you have to put optical transceivers on either side. I have a 25 foot DP cable which cost over $100, for example. So you could do a short length, high bandwidth Ethernet cable, I’m sure. But the reason we don’t is probably because differentiation between connectors is desired —- consumers are dumb, frankly. They’ll think any old Ethernet cable will work. Just look at what kind of a mess exists with USBC.
muhammadusman 3y ago
This post was informative and I didn't realize just how different DisplayPort is from HDMI. Recently, I got a desktop dock that uses DisplayPort instead of HDMI to connect to my monitor. My monitor has 2 HDMI ports, 1 Type-C, and 1 DisplayPort. So far things have been fine but I did notice that the audio is choppy no matter what I do. I thought it was the dock but audio going from my computer > dock > my webcam's speaker works fine (all over usb-c). So unfortunately, it leads me to believe that the DisplayPort is causing this jittery audio.
- smachiz 3y ago
  It might be your dock. Check to see whether it's USB or Thunderbolt. Thunderbolt docks are more expensive, but considerably more efficient and faster than USB (assuming your laptop/device supports Thunderbolt). Thunderbolt docks are basically PCIe extension devices, whereas USB docks attach everything as USB, with all the common challenges USB has on systems (like dropped audio when the CPU is busy).
  - muhammadusman 3y ago
    Thanks for the info. The dock is the CalDigit TS3 Plus dock and I’m using it with an LG monitor. Their page says it’s a Thunderbolt dock so I wonder if there’s anything else about this particular dock that could be causing this issue. Btw when the monitor was connected over HDMI, it was fine playing audio. https://www.caldigit.com/ts3-plus/ https://www.caldigit.com/ts3-plus/
    - SV_BubbleTime 3y ago
      No one would be able to answer this for you in your house with your cables with your speakers. Get another one and test it.
    - MBCook 3y ago
      That is absolutely TB and was one of the recommended docks in the Mac world for a long time. Have you talked to support? Or I wonder if it’s an issue on the LG side.
binkHN 3y ago
I didn’t realize Multi-Stream Transport (MST) requires OS support, and I was surprised to find out MacOS, with its great Thunderbolt support, does not support this. “Even” ChromeOS can do MST.
- stephenr 3y ago
  Technically macOS does support MST. But it only supports it to stitch together for a single display. It does not support daisy chaining two displays. Thankfully, every Mac for the last 7 years has Thunderbolt3 at least, so getting dual-4K-display from a single port/cable is still very doable, you just need a TB3 to dual DisplayPort or HDMI adapter.
  - bpye 3y ago
    Well except for some of the Apple Silicon machines. The M1 (and maybe M2?) only have two video output blocks, of which one is already used for the internal display. It’s honestly the biggest complaint I have about my M1 MBP. Yes DisplayLink or whatever it’s called exists but the performance is bad.
    - stephenr 3y ago
      Ugh, right. Probably a freudian slip that I just mentally pretend those configs didn't come after half a decade of ubiquitous multi-display support on Macs.
    - jon-wood 3y ago
      I assume you got one of the original M1 MBPs. The more recent models have more display blocks. M1 Pro can drive two external displays, and I think the M1 Max can do three or four. I’m still slightly pissed Apple ever shipped the original M1 MBPs, they were horrible machines.
      - spockz 3y ago
        Although I wished i would have gotten the 15” and a bigger hard drive, I’m still very happy with my first gen 13” mbp. Also the fact that I can just plug in usb c/Thunderbolt monitors and the screen just instantly displays and windows reconfigure without flickering is amazing.
tivert 3y ago
Are there any KVM switches that do Displayport well (i.e. where switching between inputs does not look like a display disconnect to the PC)? I'm still using HDMI because I like to share my home multi-monitor setup between my personal machine and my work laptop, and the KVM switches are able to fool the PCs into thinking the monitor are always connected. Years ago I tried a Displayport switch, but it could not -- I assume because if the greater sophistication of the Displayport protocol.
- mvid 3y ago
  https://store.level1techs.com/?category=Hardware https://store.level1techs.com/?category=Hardware This is what I use. It appears to disconnect, but also doesnt seem to be an issue. My machines re-organize instantly.
  - formerly_proven 3y ago
    It's gotten better in the last year or so with Windows 10 but it'll still sometimes just fall apart when the display configuration changes, which is something that just never happened for any reason with HDMI/DVI.
  - zerkten 3y ago
    I was looking at this as an upgrade pick and don't have any re-arrangement with my TESmart (TES-HDK0402A1U-USBK). What monitor(s) do you have?
  - jamestanderson 3y ago
    I got their 10gbps displayport switch to use with switching a single monitor between a Windows desktop PC and an M1 MacBook Pro. I have a 4k@144hz monitor and can get the full framerate and resolution with this setup. I've never had any problems, would highly recommend.
    - c-hendricks 3y ago
      Nice, I'll check these out. I went with an HDMI KVM and am worried about updates to HDMI making it obsolete.
hot_gril 3y ago
"We’ve all gotten used to HDMI." Well that's it then, I don't need another less common way to do the same thing. There's always that theory that low-end devices will opt for DP to avoid royalties, but the cheapest laptops and monitors tend to be HDMI-only if anything because DP is more of a special feature. Similar story with H.264/5 vs VP8/9.
- gs17 3y ago
  > There's always that theory that low-end devices will opt for DP to avoid royalties, but the cheapest laptops and monitors tend to be HDMI-only if anything because DP is more of a special feature. Yeah, when I needed a new laptop dock, one of my annoyances was having to pay extra for a DP one because our lab's IT refuses to stock adapters or cables "because people keep using them instead of returning them" and they "spent extra" to get monitors which have a single DP port.
bbx 3y ago
The reason why I switched to using the DisplayPort is that it’s the one port that supports higher refresh rates ont my Dell monitors. I didn’t realise it was more “friendly” than HDMI (which comes in various quality standards).
crazygringo 3y ago
> Just like most digital interfaces nowadays, DisplayPort sends its data in packets. This might sound like a reasonable expectation, but none of the other popular video-carrying interfaces use packets in a traditional sense – VGA, DVI, HDMI and laptop panel LVDS all work with a a stream of pixels at a certain clock rate. Funny, a stream of data at a constant rate makes much more sense to me intuitively than packets, specifically for uncompressed video. Are there any downsides to packetization, like increased latency or dropped frames or anything? Or not really, is it all upsides in being able to trivially combine multiple data streams or integrate easily into hubs?
- tverbeure 3y ago
  Latency is limited to the amount of buffering that's present in the interface logic (on sides). In the case of regular DP, there's just a few FIFOs and pipeline stages, so the latency is measured in nanoseconds. When using display stream compression (DSC), there's a buffer of 1 line, and a few FIFOs to handle rate control. At the resolution for which DSC is used (say, 4K/144Hz), the time to transmit a single line is around 3us. So that's the maximum additional latency you can expect.
- wtallis 3y ago
  > Funny, a stream of data at a constant rate makes much more sense to me intuitively than packets, specifically for uncompressed video. Sure, until you start trying to design the transceivers and realize that supporting two or three fixed standard data rates is a lot simpler than supporting a continuously-variable clock speed. Every other high-speed digital interface operates at just a few discrete speeds: SATA/SAS, PCIe, Ethernet, USB. The fact that DVI and HDMI were such a shallow digitization of VGA's racing-the-beam meant features like variable refresh rate (Gsync/Freesync) showed up far later than they should have. If we hadn't wasted a decade using CRT timings (and slight modifications thereof) to drive LCDs over digital links, it would have been more obvious that the link between GPU and display should be negotiated to the fastest data rate supported by both endpoints rather than the lowest data rate sufficient to deliver the pixels.
  - ansible 3y ago
askura 3y ago
The only downside with DP is just devices that actually have that versus HDMI / Mini hdmi. This post though has made me annoyed as DP is clearly the better standard.
- nfriedly 3y ago
  Agree with you there. I'd be much happier if my Raspberry Pis, cheap USB-C hubs, cheap monitors, etc. all had DP instead of HDMI. It's extra annoying when you realize that you're paying more for royalties and sometimes additional hardware (e.g. in a USB-C hub that uses DP internally but converts to HDMI for the output) just to get an inferior interface.
  - askura 3y ago
    Honestly, it's going to be one of those things I champion now whenever it comes up in conversation haha. Very solid points.
tshaddox 3y ago
> However, I’d like to tell you that you probably should pay more attention to DisplayPort – it’s an interface powerful in a way that we haven’t seen before. Lines like that really show just how long it can take for standards to get on the radar of mainstream tech culture. I remember hearing about and being excited about DisplayPort's move to packetized digital video in college in 2008, and seeing the first Macs with MiniDisplay port later that year (or perhaps it was in 2009)! I was actually under the impression that it has been well-known and commonplace for hobbyist and enthusiast PCs for well over 10 years, but I'm probably wrong about that!
- hot_gril 3y ago
  That, and a similar line might've been said about FireWire, which didn't really make it.
  - dylan604 3y ago
    Maybe I agree with that, but I also know that firewire helped usher in the digital video era. It allowed the transition from tape based acquisition when media cards were prohibitively expensive. Audio/Video/Deck control all down one single cable straight from the camera to the computer was what really kicked the prosumer market into being able to lean closer to pro than consumer. Now that media cards are actually affordable, that does seem like ancient history. I could see how you might think of firewire as a failure if you're looking at it as a USB type transition, but for the camera/video professions, it served a very good purpose even if short lived
    - pdmccormick 3y ago
      I once purchased a FireWire multi-channel audio interface with the express intent of reverse engineering the protocol in order to add Linux support. I purchased a specialized PCI card that was intentionally non-standard (not OHCI 1394) but could snoop and capture traffic between a device and a host. I chipped away at deciphering a register map for awhile, but eventually better USB audio devices came along that had more driver support. Still trying to do the same sort of thing though with some audio related USB and Ethernet/IP devices so I guess I never really gave up the idea in my heart!
hooverd 3y ago
For a brief moment, being able to daisy-chain displays was so cool. Now it feels like we've regressed to wrangling HDMI cables out of a USB-C hub.
TazeTSchnitzel 3y ago
The amazing thing about DVI, and by extension HDMI, is that it's just VGA but digital, with all the timing and synchronisation complexity that implies. Recall that DVI can have both an analog (VGA/DVI-A) and digital (DVI-D) signal in the same cable. They aren't independent; they share some pins and have the same timing. You could have made a CRT monitor that used DVI-D just by adding a DAC, though I'm not sure if anyone ever did. DisplayPort does away with all that legacy. I assume the hardware to implement it is much simpler and more reliable.
- pavlov 3y ago
  I was guessing that the oddly beautiful 17” Apple CRT Studio Display [1] from 2000 might have been a CRT that used a digital signal cable because it had the short-lived Apple Display Connector, but apparently ADC carried analog too. [1] https://everymac.com/monitors/apple/studio_cinema/specs/apple_studio_display_17_cl.html https://everymac.com/monitors/apple/studio_cinema/specs/appl...
  - ShadowBanThis01 3y ago
    The ADC carried power, too, which is why Apple went with it.
- MisterTea 3y ago
  > You could have made a CRT monitor that used DVI-D just by adding a DAC, though I'm not sure if anyone ever did. From memory IBM offered a crt with DVI.
  - thereddaikon 3y ago
    Plenty did but they were usually DVI-A or DVI-I
- madars 3y ago
  This also has side-channel implications, and is a reason why eDP is recommended in voting applications. https://www.eerstekamer.nl/nonav/overig/20160428/richtlijnen_ter_voorkoming_van/document https://www.eerstekamer.nl/nonav/overig/20160428/richtlijnen... >DisplayPort uses a scrambler as part of its line encoding in order to flatten the Fourier spectrum of its emissions and suppress spectral peaks caused by particular image contents. This reduces the chances of any particular image content causing a problem spectral peak during SDIP-27 and EMI spectrum measurements. According to the standard, the scrambler reduces spectral peaks by about 7 dB. As a side effect, the scrambler also makes it far more difficult, probably even impractical, for an attacker to reconstruct any information about the displayed image from the DisplayPort emissions. [..] DisplayPort uses a small number of fixed bit rates, independent of the video mode used. Unlike with most other digital interfaces, video data is transmitted in data packets with header and padding bytes, and not continuously with a television-like timing. As a result, DisplayPort cables are not a common source of van-Eckstyle video emanations and this again will make it very hard for an eavesdropper to synchronize to the transmitted data. Speaking of which: how does one force HDCP (say, in Linux)? That would transform this technology from a DRM nuisance (strippers easily available on AliExpress) into a Van Eck-countermeasure.
spearman 3y ago
> A carefully shaped money-backed lever over the market is absolutely part of reason you never see DisplayPort inputs on consumer TVs, where HDMI group reigns supreme What does this actually mean?
- green-salt 3y ago
  HDMI is licensed, Displayport doesn't need one. I'm sure there's money changing hands in the TV sector of most display manufacturers.
shmerl 3y ago
> Plus, It’s Not HDMI This. HDMI and its cartel that profits from its patents are super annoying.
chx 3y ago
> However, if you don’t need the full bandwidth that four lanes can give you, a DP link can consist of only one or two main lanes resulting in two This is how many USB C docks operate. The USB C connector also has four high speed lanes and there's a mode where two are assigned to carry DisplayPort data and two are assigned to be TX and RX respectively for USB. Until DP 1.4 appeared, this meant you were quite limited in display resolution if you didn't have Thunderbolt and wanted faster than 480mbps data speed. With DP 1.3, two HBR3 lanes can carry 12.96 Gbit/s which is almost exacly the requirement for 4k @ 60Hz at 12.54 Gbit/s. DP 1.4 adds compression on top of this. One more beauty of DisplayPort is it's point to point so it's entirely possible your USB C hub will carry the display data from the host to the hub as compressed HBR3 data over two lanes and then hand it out to two monitors over four uncompressed HBR2 lanes to each so a modern USB C hub can, without Thunderbolt, drive two 4k @60Hz monitors and still provide multiple gigabit speed data. It's a very neat trick. This needs full DisplayPort 1.4 support including DSC in the host, for integrated GPUs in laptop CPUs this means AMD Ryzen 4000 and newer or Intel Tiger Lake and newer (older laptops with discrete GPUs might have had it, too). Handy tip: if your hub is DP 1.4 and drives multiple monitors then it's most likely using a Synaptics MST hub to do this (almost all non-Thunderbolt ones do and many Thunderbolt ones as well) and Synaptics provides a very very little known diagnostics tool called vmmdptool (available in the Windows Store). It doesn't replace a full DP AUX protocol analyzer of course but it's free and for that price it's really handy. This topic is dear to me because I have fixed the USB C specification related to this and allow me to be damn proud of that: it used to erroneously say the USB data speed in this mixed functionality was limited to 5gbps but it is not, the limit is 10gbps. https://superuser.com/a/1536688/41259 https://superuser.com/a/1536688/41259 Ps.: When I say Thunderbolt, I am well aware of how Thunderbolt 4 is just USB4 with optional features made mandatory. It's not relevant to the discussion at hand. Pps.: DisplayPort is the native video standard for USB C, C-DisplayPort adapters and cables are basically passive because they just need to tell the host how to configure the connector lanes. Meanwhile all USB C - HDMI cables and converters are active which constantly work on the DP signal to become HDMI. DisplayPort++ alas is not implemented with the USB C connector. For this reason if any compatibility issues arise it's always better to connect a USB C device to the DisplayPort input on a monitor. A HDMI alternate mode was defined in the past but it remained paper only and it has been declared dead this year at CES.
Sparkyte 3y ago
my argument display-port of usb-c is a better interface for flexibility and utility
Ajedi32 3y ago
> A carefully shaped money-backed lever over the market is absolutely part of reason you never see DisplayPort inputs on consumer TVs, where HDMI group reigns supreme, even if the TV might use DisplayPort internally for the display panel connection. Curious about this. Is the HDMI standards group engaging in anti-competitive behavior to prevent DisplayPort from taking over on TVs? I've always assumed it was just momentum.
- msie 3y ago
  I was just thinking about USB-C vs Lightning... What if the EU were to mandate HDMI over DisplayPort?
  - Dr4kn 3y ago
    The EU Generally chooses the more open and cheaper alternative. They did this with phone charging, car charging and would probably do the same with display connectors. USB C is the cheaper and more capable connector
- 6D794163636F756 3y ago
  Another key is that HDMI carries more power than display port. There are dongles for your tv that can get all the power they need from an HDMI cable. Not so far display port. When it comes to use case, display port is better when connecting a fully independent device to a display and HDMI is better for connecting a peripheral to a system
  - cesarb 3y ago
    > Another key is that HDMI carries more power than display port. A quick look at Wikipedia's article for both standards shows that you're wrong: DisplayPort: 3.3 V ±10%, 500 mA HDMI: 5 V, 50 mA Which means at least 1500 mW for DisplayPort, and only 250 mW for HDMI. So no, the DisplayPort cable carries more power than the HDMI cable. And when you think about it a bit, it makes sense that DisplayPort carries more power than HDMI: one of the use cases for DisplayPort is an active converter to HDMI, which needs power for both its electronics and the HDMI cable.
deleted 3y ago
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dsab 3y ago
I hate HDMI, I had many problems with this interface, in my prvious job my monitor was turning off when I was getting up from chair, same was happening in my home with differeng PC, cables and monitor. Such a thing never happend to me when I changed interface to Display Port
sylware 3y ago
Don't forget, displayport is worldwide royalty free, not hdmi (similar issue than mpeg/av1, arm|x86/risc-v, etc).
qwertox 3y ago
This is a really well written article. If you haven't bothered reading about DisplayPort because you knew VGA, somewhat knew DVI and thought that HDMI is the culmination of it all, where then DisplayPort is just some further kind of evolution, this article does a really good job at explaining how DP is very different and something new, something worth knowing about. The core sentence which made me actually read the article was "DisplayPort sends its data in packets." and does a good job at explaining what this means and how this differs from HDMI.
- ben0x539 3y ago
  As a habitual comments skimmer, thanks for selling me on the article. :)
- zsz 3y ago
  I've run into problems repeatedly when it came to DP cables. The issue is always the same: lack of enforcement and no barrier to entry allows for too many entrants, whose motives are up to consumers to discern, wasting time and money in the process. What I originally saw as a benefit of an open standard, as it turned out, was in fact a benefit (for consumers like myself) of the closed/high priced standard—which ended up costing me less, in the process. Something the original article doesn't mention regarding multi-stream (MST) is that it could be used in situations where a defined standard for a certain resolution/refresh rate didn't even exist, to still make it available. For example, the earliest 4K/60Hz monitors relied on DP 1.4's (or 1.2's? I don't remember) ability to address multiple displays, to send two signals—each to cover one half of the total screen area, i.e. 1920x2160/60Hz, for a combined total of 3840x2160/60Hz—to the same display, which that display then used to internally drive two virtual screens, added seamlessly to create 3840x2160/60Hz. At the time (around 2013 and for a while thereafter), the maximum supported in single stream configuration (or by the existing HDMI standard at the time)_was 3840x2160/30Hz. You'd think this would be a point in favor of DP—which is certainly what I assumed, at the time. Unfortunately it soon became obvious that because there was no enforcement of DP compatibility—of claiming to support up to a certain version of DP fully, in other words—this meant that most cable manufacturers felt no compunction about lying shamelessly, claiming to support e.g. the 1.2 or 1.4 version at the time (which implied supporting its MST and bandwidth capabilities fully), while doing nothing of the sort. The lies did not stop there, by the way. If I could, I would here post a photo that I would happily take this very moment of such a DP cable—which didn't come especially cheap at the time, btw., in fact it took three days' worth of effort, a lot of handwringing and plain luck in the end (not to mention wasting money on several dud cables, each claimed to be fully compliant, on top of the additional money required) to finally purchase a cable that actually was compliant—which claimed gold plating as one of its features. Some fine gold that was, with black spots on both sides of the yellowish anodized plug, where the metal had oxidized! Why? Because, as I came to realize, the high barrier to entry created by the high licensing fee of the HDMI group also acts to keep away a bunch of unscrupulous manufacturers, which is purely a benefit to consumers! In addition, I've never had problems with regular size HDMI plugs—in particular, with removing them. I can't say the same when it comes to DP (especially full sized), which frequently (by design?) have a button that needs to be pushed in to release a lock that holds the plug in place. The problem is, too many times it's very difficult, if not impossible, to push down this button. Worse yet is the ambiguity that this creates: is the button fullly depressed? Is it stuck? Am I getting ready to rip out, or at least damage the underlying hardware, or even just the cable itself? These are thoughts I've had nearly every time while trying to unplug a DP cable, while HDMI (at least the standard size) slides out smoothly, as nothing is put in place to hinder this. In addition, this works well time after time, meaning there is no mechanical fatigue like with mini- and mico-USB. I can appreciate the idea that DP, when used internally (e.g. in laptops, where any shortcoming would directly reflect on the manufacturer of that laptop), or embedded within another standard, is a great idea, where its low barrier to entry /can be/ (as long as the savings are passed on, that is) a benefit to consumers. However, to claim the same in all applications is simply not supported by the real life outcome of either implementation philosophy.
cat_plus_plus 3y ago
Maybe it is, but I also want audio, so the point is moot.
- goombacloud 3y ago
  Audio is covered as well, as written in the article, I recommend reading it.
rbanffy 3y ago
I was very disappointed that HDMI transfers a constant bit-rate stream of pixels - VGA, but digital. I expected that, given most display devices can at least hold a full frame in-memory, that the stream could be limited to the parts of the image that changes, allowing higher frame rates when less than the full frame changes. That, and generating a signal could be much simpler than bit-banging on a DAC.
amelius 3y ago
Can we please get monitors that can find their signal within 100ms? Can we please get monitors that communicate their orientation (portrait/landscape etc.) to the computer?
- jwells89 3y ago
  The Apple Studio Display autodetects rotation and lets the connected computer know so it can adjust the picture accordingly, but it connects over Thunderbolt. It should be possible for monitors to do this over USB-C too, but I’m not sure about plain DisplayPort or HDMI.
  - gsich 3y ago
    I2C (Aux) could do this.
  - theodric 3y ago
    sigh Ok FINE I will move the goalpost I want all that in a monitor that doesn't cost more than a typical modal monthly income in Europe
    - mickelsen 3y ago
      Not Europe but Latin America, still even taking the US into account... man, the monitor market is so bad! Mass items still stuck in low resolutions, 4k goes way up, and not so many options. I mean I get it's not the TV market, but it does feel more niche compared to 10 years ago. The earliest used iMacs with 5K displays seem consistent options on the affordable side tho, and better than test-driving a possible lemon from DELL/HP/Spectre or a middle range panel from Samsung/LG.
  - deergomoo 3y ago
    > it connects over Thunderbolt Not exclusively—it supports regular DP Alt Mode, though no idea if those advanced features also work.
- deergomoo 3y ago
LelouBil 3y ago
A friend of mine had problems with his monitor, it would go into standby randomly when running certain games. I asked him for details about his setup and I was pretty confused when he said the connector at the back of his monitor had screws but I saw the Nvidia control panel reporting HDMI. Turns out he was using an HDMI to VGA adapter ! (GPU was outputting HDMI and screen consumed VGA). I just told him to go buy a display port cable (since his GPU and monitor both had it) and he had no problem since. Does anyone have insight about why the adapter could cause monitor standby in certain games ? It is really a peculiar issue.
- tormeh 3y ago
  Huh, I have the same issue with pure HDMI. No clue what the reason is.
nyanpasu64 3y ago
> If you see a DisplayPort interface on your board where you’d usually expect HDMI, that might just be because the company decided to avoid HDMI’s per-device royalties, and do firmly believe that this is a good thing. Wikipedia says DP 1.3 requires "mandatory Dual-mode for DVI and HDMI adapters". Does this mean that all DP 1.3 ports must output HDMI (and presumably pay HDMI licensing fees) as well?
somat 3y ago
The article missed the most important advantage of display port over hdmi, you can get locking connectors. I joke of course, but of the two standards bodies vesa always feels like they were less interested in playing the drm game and more interested in making a useful standard.
- justusthane 3y ago
  It’s mentioned towards the beginning: > Physically, desktop/laptop DisplayPort outputs come in two flavors – full-size DisplayPort, known for its latches that keep the cable in no matter what, and miniDisplayPort But yeah, the latches are great.
uglycoyote 3y ago
in my experience HDMI works better. I have had Dell 4K monitors both at my home and my work, on three different PCs all have the exact same issue: with DisplayPort I can't get more that 30hz and the mouse is so delayed that it is practically unusable. I almost sent the first monitor back, but when I decided to try the supposedly-inferior HDMI I had no trouble driving it at 60hz and the mouse movement feels buttery smooth (no latency). it's not a case of a weak video card... my card at work easily drives two of these 4K screens at 60 hz over HDMI but for some reason can't drive a single 4K monitor at more than 30 on DisplayPort. what's up with that?
nathants 3y ago
1440p 240hz is currently where it tops out. to be fair, this is a fantastic format.
fake-name 3y ago
I strongly disagree with the basic thesis of this article. HDMI is better then displayport. DVI is better then HDMI. USB-C is a complete disaster (particularly when trying to tunnel displayport). I have an ongoing hypothesis that the general robustness and pleasantness-of-use of a computer interface which will be implemented by multiple separate vendors is inversely proportional to it's complexity. As the interface protocol gets more complicated, it inevitably winds up with progressively more terrible implementations. As you add more vendors implementing the same protocol, or more features to the same protocol, the likelihood of two vendors or two implementations by the same vendor finding a corner case where they fail to interoperate properly approaches 1. I use dell laptops at work. Dell cannot get their own laptops to tunnel displayport over USB-C reliably to their own dell branded docks. Additionally, if you have an nvidia GPU, certain displayport errors will BSOD the entire computer. *Yes, plugging in a slightly misbehaving display can crash your computer entirely*. Displayport is a nightmare from the consumer's perspective. Will two displayport devices properly negotiate <feature>? Who knows?
rustybolt 3y ago
Praise displayport all day if you want, but the connector sucks and the protocol is too complicated (protip: when something in IT is called "powerful" you probably want to steer clear of it). It is much more convenient and practical to have data streams like VGA and DVI have.
phkahler 3y ago
They specifically mention 3 distinct DP connectors - standard, mini, USB-C - plus a bunch of Apple versions of them. That's NOT a feature and is exactly why I prefer HDMI. I don't care about most DP capabilities, I just want to plug in my stuff and have it work. I use 55" 4k TV for a monitor and it works, even with the open source AMD driver. I saw nothing in TFA to make me think DP would benefit me, even if some technical details are better.
- dawidpotocki 3y ago
  But, HDMI has multiple connectors too. HDMI, Mini HDMI, Micro HDMI, USB HDMI Alt-mode and there are also some less popular ones.
mensetmanusman 3y ago
Our work went DP on all laptops years ago but then didn't add adapters to the projectors or TVs, so everyone complained and then the newest laptops are back to hdmi and usb. Be smart people!
svlasov 3y ago
Is there an affordable 4-port DisplayPort 1.4 switch? How are they almost 10x more expensive than HDMI variants? Paying 500€ for a KVM box is not justifiable, I only want to avoid physically re-plugging the cables.
djmips 3y ago
Even the latest consoles like XBox Series X and PS5 have HDMI only outputs!
Dwedit 3y ago
So if HDMI is so restricted with NDAs, how is DisplayPort allowed to have a documented compatibility mode for it?
unstatusthequo 3y ago
Good and interesting video to explain the version diffs in spec: https://www.youtube.com/watch?v=Vn2vdQZhs0w&ab_channel=LinusTechTips https://www.youtube.com/watch?v=Vn2vdQZhs0w&ab_channel=Linus... And even better, a calculator based on your monitor capabilities that helps you choose: https://linustechtips.com/topic/729232-guide-to-display-cables-adapters-v2/ https://linustechtips.com/topic/729232-guide-to-display-cabl... I ended up with a $15 2.0 10 foot cable from Monoprice. Fit my ultra wide Samsung G9 pixel pushing needs just fine.
corajoe 3y ago
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maria1998zx 3y ago
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maria1998zx 3y ago
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828 points by zdw 3y ago

bee_rider 3y ago

I just like the little retaining clips, and the satisfying little click you hear/feel when plugging them in.

green-salt 3y ago
I have a love/hate relationship with them for when the release tab is in a hard to reach area or doesn't release well, but that's usually the cable's fault. Love that tactile sensation of it being properly mated.
ComputerGuru 3y ago
It’s a problem when the x16 slot is the bottom-most and the orientation is such that the clicky thing you must depress is on the bottom side of the DP connector when plugged in, and your case has a ledge after the PCI slots so you cannot realistically depress the latch. Of course, no one would realistically encounter a case/GPU/cable combo like that. Right?
- jacquesm 3y ago
  Hm, my sample for that situation clocks in at about 100% (n=1). Especially the first time I needed to unplug that cable I was thrown for a bit, I ended up taking the whole case off the floor and using a thin screwdriver to depress the release button from the exposed side, that did the trick.
- NavinF 3y ago
  Your GPU should be in the x16 slot closest to the CPU because it has the most bandwidth. tbh this sounds like a self-inflicted SFF build problem
  - sokoloff 3y ago
    If you have multiple GPUs in a box, you often have to use the bottom slot as well as the close one. (Passing through dedicated GPUs to different VMs is one case that I’ve experienced.)
  - ComputerGuru 3y ago
    > tbh this sounds like a self-inflicted SFF build problem No, the error is in automatically assuming that the GPU should be the one to get the x16 port. This is a tower server; the x16 and x8 ports are for the SAS cards, network cards, and NVMe drives. The GPU takes whatever is left.

deleted 3y ago

[deleted]

BadBadJellyBean 3y ago

I just wish there was only one connector. Either HDMI or DP. I don't care.

eviks 3y ago
Why don't you care if it's a worse one?
jayd16 3y ago
It'll be the USB-C port.
- FinnKuhn 3y ago
  and USB-C allows the transmission of displayport over USB-C
  - jsheard 3y ago
    It also allows the transmission of HDMI over USB-C, so you still have two competing standards
    - hadrien01 3y ago
      There's also Thunderbolt over USB-C that does DisplayPort, but it doesn't support all the same versions as DisplayPort over USB-C. And there's also USB 4 but I don't know/understand if it changes anything.
      - masklinn 3y ago
        I think the most applicable bit is that USB4 adds tunneling modes, aside from alternate mode. I'm not entirely clear, but from my understanding alternate mode means the physical connection gets switched over, while tunneling means the tunneled data is sent over USB (so the communication on the wire is USB all along, you get nesting).

gaudat 3y ago

I really really hope that my LG has a DisplayPort input. They do offer a monitor that is the same size and I believe the same panel, but the price increase does not really justify it. So sad that I have to bear with the hell of DP/USBc to HDMI converters...

andelink 3y ago
You hope? You’re not able to look at the specs before buying?

LoveMortuus 3y ago

I personally prefer HDMI or DVI, I don't like DisplayPort because on the display that I have, when I turn off the display the computer detects it as if I've physically disconnected the display, which then moves all the windows that I had open around and breaks my macros...

vel0city 3y ago
That's a failure of the display or your GPU, not necessarily the port. I've got several monitors with DisplayPort on a few different GPUs that don't do this behavior. Its not something inherent with DisplayPort.
Aaargh20318 3y ago
Sounds like an OS problem. When I do that it moves all open windows to the remaining display, but when I turn the other display back on it just moves them back. No special software installed for this, just stock macOS Ventura.
- LoveMortuus 3y ago
  But when I turn off my displays that are on HDMI or DVI or VGA, the computer still detects them like normal, like they're connected, because they are. I don't understand in which case the 'act like it's physically disconnected' behaviour would be more desired than what we had with all the standards before. I have read that some DisplayPort displays do have an option in the settings to disable this behaviour.
  - Aaargh20318 3y ago
    > But when I turn off my displays that are on HDMI or DVI or VGA, the computer still detects them like normal, like they're connected, because they are. But since they’re off, that doesn’t make any sense, now you can’t reach any windows on those monitors. I think the macOS behavior make the most sense, move them so you can access them, but move them back once the display is turned on.

Veliladon 3y ago

HDMI predates DP by 5 years, switching wouldn't enable any specific use case, and that 5 years head start means HDMI has market inertia. Yes we should use it because it's better but the practicality? There's so much gear that's HDMI that would have to be replaced or require new active adaptors. It's so much industry and consumer effort for such a marginal gain.

lucideer 3y ago
Forget all the other pros/cons - MST makes it worth any industry & consumer effort alone.
- hot_gril 3y ago
  How many people use multiple external displays? For the power users who do, there are already good enough solutions.
  - lucideer 3y ago
    I don't have data on this but if my anecdata is anything to go by, power users aren't your typical multi-monitor users...
patrickthebold 3y ago
My monitor is fairly old, but it only does 30Hz on the hdmi cable and 60Hz on the display port cable. I'm not sure the exact versions. I think its displayport 1.2 and HDMI < 2. So for me, it was super important to get display port out.
metaphor 3y ago
> HDMI predates DP by 5 years... - HDMI v1.0 initial release = 2002-12-09 - DisplayPort v1.0 initial release = 2006-05-01 To be sure, just under 3.5 years; HDMI rolled into v1.3 a month after DisplayPort v1.0 saw the light of day. Agreed on the impact of market inertia.
- 3y ago

remix2000 3y ago

With HDMI, I have both video and audio traveling over a single cable. That is _extremely_ convenient. DP _theoretically_ supports audio too, but AFAIK that's not widely implemented.

lucideer 3y ago
> That is _extremely_ convenient. I'm open to having my mind changed but I have not really experienced this extreme convenience in practice. The vast majority of things I plug a HDMI cable into either don't have speakers or if they do, the speakers are a bad quality afterthought. In actual fact, what has been an extreme inconvenience is the OS thinking I want HDMI audio instead of whatever much higher-quality* alternative output I actually want to direct my audio to. The only time I've ever gotten high-quality audio output over HDMI is via ARC, which says a lot about the need for HDMI audio... * When I say "much higher-quality", I don't mean HDMI is a low-quality audio transport, I mean the HDMI output devices more often than not have inferior audio output to some other bluetooth / 3.5mm jack device I am using.
- taeric 3y ago
  It was very convenient for me to have my headphones plugged into the monitor. Made it so I could plug a single cable over to my laptop and have basically everything else already done.
  - lucideer 3y ago
    > headphones plugged into the monitor That sounds cool but I've never see a monitor with a jack. Mine all have many USB ports, but not audio. How common are they?
    - yonatan8070 3y ago
      I have a 144Hz 1080p AOC monitor and a secondary generic LG one, both have an audio jack
    - sublinear 3y ago

nfriedly 3y ago

I'm annoyed nvidia for putting the current generation of HDMI on their recent GPUs, but leaving them with an outdated version of DisplayPort. For a long time, my advice to anyone was to always choose DisplayPort whenever it was an option. But now that has to have the caveat of "if you have a new high-end GPU and a fancy high refresh rate monitor, HDMI might actually be better for your situation"

gjsman-1000 3y ago
> I'm annoyed nvidia for putting the current generation of HDMI on their recent GPUs, but leaving them with an outdated version of DisplayPort. That was due to unfortunate timing where HDMI had the specifications ready before DisplayPort did.
- Sweepi 3y ago
  AMD’s RX 7000 support Display port 2.0 and were released 2 months later then Nvidia’s Ada. Afaik DP 2.0 has been finished in 2019(!).
- Night_Thastus 3y ago
  I thought it was because their G-Sync modules had not been updated to support the new DP? That was what I heard.
111111IIIIIII 3y ago
And only 1 new version HDMI port but 3 old version DP ports. I use a dual display setup but HDR only works on mu displays with HDMI.
- Strom 3y ago
  The more expensive Gigabyte RTX 3080+ cards had 3x DP 1.4, 2x HDMI 2.1, 1x HDMI 2.0, which was great even if you could only use 4 of them at the same time due to Nvidia limitations. Unfortunately for the 40 series they stopped offering it and now they're the same as stock Nvidia with 3x DP 1.4, 1x HDMI 2.1. Luckily ASUS still offers a bit more with their 4080+ cards - 2x HDMI 2.1, 3x DP 1.4. I personally depend on the 2x HDMI 2.1 to even be able to run my 4K 144Hz monitors at full speed.

wcfields 3y ago

If we lived in a just, and virtuous world we'd all be using cheap coaxial cables with BNC connectors via whatever version of SDI is the highest bit rate.

mschuster91 3y ago
SDI can't do any communication between the source and sink. You can do a limited form if you use two SDI cables (one upstream, one downstream) which is what stuff like BlackMagic's bi-directional micro converter does, but IIRC that's only used for talkback to the camera operator and HDMI CEC messages which is how they implement things like their ATEM Mini consoles triggering recording - not for DDC-style format and framerate negotiations. Also, device manufacturers don't do SDI on consumer devices because SDI is by definition unencrypted and uncompressed, so it's at odds with HDCP. [1] https://www.blackmagicdesign.com/products/microconverters https://www.blackmagicdesign.com/products/microconverters
- ShadowBanThis01 3y ago
  BMD has done some innovative things through their SDI port, specifically enabling camera control with an Arduino-add-on board. Someone finally did what I've wanted to see for years: built a follow-focus unit that controls the focusing motors in the lenses, so you don't have to bolt a ridiculous contraption (and janky focusing-ring adapters) onto a lens to turn its (non-mechanical) focusing ring manually.
  - mschuster91 3y ago
    What I want to see is someone dump the FPGA in these Micro Converters and hack it to add an USB interface. The Micro Converters are all just the same in the interior: SerDes units and clock/redrivers on the I/O ports and an FPGA that additionally has an USB connection which is used to power the converter but could also be used to do other things. That FPGA should be powerful enough to do a lot of interesting things - anything from fooling around with commands (like with the Arduino board) to image manipulation (e.g. a watermark embed).
3y ago

mschuster91 3y ago

> in fact, the first time we mentioned eDP over on Hackaday, was when someone reused high-res iPad displays by making a passthrough breakout board with a desktop eDP socket. Yes, with DisplayPort, it’s this easy to reuse laptop and tablet displays – no converter chips, no bulky adapters, at most you will need a backlight driver. I'm a bit confused by the linked project's PCB [1] - if all that's needed is a backlight driver, why all the differential pairs between the microcontroller and the eDP FFC? [1] https://hackaday.io/project/369/gallery#9e4a0fef705befb8030b2eee0dda0825 https://hackaday.io/project/369/gallery#9e4a0fef705befb8030b...

bpye 3y ago
The schematics are available [0]. It looks to me like the MCU is doing some sideband control, but the DisplayPort signal itself is passed through unmodified. [0] https://github.com/OSCARAdapter/OSCAR https://github.com/OSCARAdapter/OSCAR

pid-1 3y ago

Sorry if that sounds stupid, but why isn't Ethernet used for this sort of high bw signaling?

fsh 3y ago
The bandwidth is much too low.
- londons_explore 3y ago
  If this were true, then people would be running datacenter networking over HDMI. Data is data - there is no benefit to designing two entirely different transport mechanisms for video vs other data. You could argue that video data has a deadline to meet - but ethernet already has lots of mechanisms for QoS and bandwidth reservations to make sure that someones torrents don't interrupt something latency sensitive. Sure, they aren't widely supported over the internet, but between your PC and your display - they can be engineered to work properly.
  - wmf 3y ago
    25 Gigabit Ethernet costs ~100x more than 32 Gigabit Displayport.
    - aidenn0 3y ago
      Sounds like the real question is why don't people use DP for p2p networking links...
      - xienze 3y ago
        There’s nothing magic about DP cables, they’re just typically a short-ish length, which is why they can be high bandwidth and relatively cheap. Once you get to a decent length, the cables get really expensive because you have to put optical transceivers on either side. I have a 25 foot DP cable which cost over $100, for example. So you could do a short length, high bandwidth Ethernet cable, I’m sure. But the reason we don’t is probably because differentiation between connectors is desired —- consumers are dumb, frankly. They’ll think any old Ethernet cable will work. Just look at what kind of a mess exists with USBC.

muhammadusman 3y ago

This post was informative and I didn't realize just how different DisplayPort is from HDMI. Recently, I got a desktop dock that uses DisplayPort instead of HDMI to connect to my monitor. My monitor has 2 HDMI ports, 1 Type-C, and 1 DisplayPort. So far things have been fine but I did notice that the audio is choppy no matter what I do. I thought it was the dock but audio going from my computer > dock > my webcam's speaker works fine (all over usb-c). So unfortunately, it leads me to believe that the DisplayPort is causing this jittery audio.

smachiz 3y ago
It might be your dock. Check to see whether it's USB or Thunderbolt. Thunderbolt docks are more expensive, but considerably more efficient and faster than USB (assuming your laptop/device supports Thunderbolt). Thunderbolt docks are basically PCIe extension devices, whereas USB docks attach everything as USB, with all the common challenges USB has on systems (like dropped audio when the CPU is busy).
- muhammadusman 3y ago
  Thanks for the info. The dock is the CalDigit TS3 Plus dock and I’m using it with an LG monitor. Their page says it’s a Thunderbolt dock so I wonder if there’s anything else about this particular dock that could be causing this issue. Btw when the monitor was connected over HDMI, it was fine playing audio. https://www.caldigit.com/ts3-plus/ https://www.caldigit.com/ts3-plus/
  - SV_BubbleTime 3y ago
    No one would be able to answer this for you in your house with your cables with your speakers. Get another one and test it.
  - MBCook 3y ago
    That is absolutely TB and was one of the recommended docks in the Mac world for a long time. Have you talked to support? Or I wonder if it’s an issue on the LG side.

binkHN 3y ago

I didn’t realize Multi-Stream Transport (MST) requires OS support, and I was surprised to find out MacOS, with its great Thunderbolt support, does not support this. “Even” ChromeOS can do MST.

stephenr 3y ago
Technically macOS does support MST. But it only supports it to stitch together for a single display. It does not support daisy chaining two displays. Thankfully, every Mac for the last 7 years has Thunderbolt3 at least, so getting dual-4K-display from a single port/cable is still very doable, you just need a TB3 to dual DisplayPort or HDMI adapter.
- bpye 3y ago
  Well except for some of the Apple Silicon machines. The M1 (and maybe M2?) only have two video output blocks, of which one is already used for the internal display. It’s honestly the biggest complaint I have about my M1 MBP. Yes DisplayLink or whatever it’s called exists but the performance is bad.
  - stephenr 3y ago
    Ugh, right. Probably a freudian slip that I just mentally pretend those configs didn't come after half a decade of ubiquitous multi-display support on Macs.
  - jon-wood 3y ago
    I assume you got one of the original M1 MBPs. The more recent models have more display blocks. M1 Pro can drive two external displays, and I think the M1 Max can do three or four. I’m still slightly pissed Apple ever shipped the original M1 MBPs, they were horrible machines.
    - spockz 3y ago
      Although I wished i would have gotten the 15” and a bigger hard drive, I’m still very happy with my first gen 13” mbp. Also the fact that I can just plug in usb c/Thunderbolt monitors and the screen just instantly displays and windows reconfigure without flickering is amazing.

tivert 3y ago

Are there any KVM switches that do Displayport well (i.e. where switching between inputs does not look like a display disconnect to the PC)? I'm still using HDMI because I like to share my home multi-monitor setup between my personal machine and my work laptop, and the KVM switches are able to fool the PCs into thinking the monitor are always connected. Years ago I tried a Displayport switch, but it could not -- I assume because if the greater sophistication of the Displayport protocol.

mvid 3y ago
https://store.level1techs.com/?category=Hardware https://store.level1techs.com/?category=Hardware This is what I use. It appears to disconnect, but also doesnt seem to be an issue. My machines re-organize instantly.
- formerly_proven 3y ago
  It's gotten better in the last year or so with Windows 10 but it'll still sometimes just fall apart when the display configuration changes, which is something that just never happened for any reason with HDMI/DVI.
- zerkten 3y ago
  I was looking at this as an upgrade pick and don't have any re-arrangement with my TESmart (TES-HDK0402A1U-USBK). What monitor(s) do you have?
- jamestanderson 3y ago
  I got their 10gbps displayport switch to use with switching a single monitor between a Windows desktop PC and an M1 MacBook Pro. I have a 4k@144hz monitor and can get the full framerate and resolution with this setup. I've never had any problems, would highly recommend.
  - c-hendricks 3y ago
    Nice, I'll check these out. I went with an HDMI KVM and am worried about updates to HDMI making it obsolete.

hot_gril 3y ago

"We’ve all gotten used to HDMI." Well that's it then, I don't need another less common way to do the same thing. There's always that theory that low-end devices will opt for DP to avoid royalties, but the cheapest laptops and monitors tend to be HDMI-only if anything because DP is more of a special feature. Similar story with H.264/5 vs VP8/9.

gs17 3y ago
> There's always that theory that low-end devices will opt for DP to avoid royalties, but the cheapest laptops and monitors tend to be HDMI-only if anything because DP is more of a special feature. Yeah, when I needed a new laptop dock, one of my annoyances was having to pay extra for a DP one because our lab's IT refuses to stock adapters or cables "because people keep using them instead of returning them" and they "spent extra" to get monitors which have a single DP port.

bbx 3y ago

The reason why I switched to using the DisplayPort is that it’s the one port that supports higher refresh rates ont my Dell monitors. I didn’t realise it was more “friendly” than HDMI (which comes in various quality standards).

crazygringo 3y ago

> Just like most digital interfaces nowadays, DisplayPort sends its data in packets. This might sound like a reasonable expectation, but none of the other popular video-carrying interfaces use packets in a traditional sense – VGA, DVI, HDMI and laptop panel LVDS all work with a a stream of pixels at a certain clock rate. Funny, a stream of data at a constant rate makes much more sense to me intuitively than packets, specifically for uncompressed video. Are there any downsides to packetization, like increased latency or dropped frames or anything? Or not really, is it all upsides in being able to trivially combine multiple data streams or integrate easily into hubs?

tverbeure 3y ago
Latency is limited to the amount of buffering that's present in the interface logic (on sides). In the case of regular DP, there's just a few FIFOs and pipeline stages, so the latency is measured in nanoseconds. When using display stream compression (DSC), there's a buffer of 1 line, and a few FIFOs to handle rate control. At the resolution for which DSC is used (say, 4K/144Hz), the time to transmit a single line is around 3us. So that's the maximum additional latency you can expect.
wtallis 3y ago
> Funny, a stream of data at a constant rate makes much more sense to me intuitively than packets, specifically for uncompressed video. Sure, until you start trying to design the transceivers and realize that supporting two or three fixed standard data rates is a lot simpler than supporting a continuously-variable clock speed. Every other high-speed digital interface operates at just a few discrete speeds: SATA/SAS, PCIe, Ethernet, USB. The fact that DVI and HDMI were such a shallow digitization of VGA's racing-the-beam meant features like variable refresh rate (Gsync/Freesync) showed up far later than they should have. If we hadn't wasted a decade using CRT timings (and slight modifications thereof) to drive LCDs over digital links, it would have been more obvious that the link between GPU and display should be negotiated to the fastest data rate supported by both endpoints rather than the lowest data rate sufficient to deliver the pixels.
- ansible 3y ago

askura 3y ago

The only downside with DP is just devices that actually have that versus HDMI / Mini hdmi. This post though has made me annoyed as DP is clearly the better standard.

nfriedly 3y ago
Agree with you there. I'd be much happier if my Raspberry Pis, cheap USB-C hubs, cheap monitors, etc. all had DP instead of HDMI. It's extra annoying when you realize that you're paying more for royalties and sometimes additional hardware (e.g. in a USB-C hub that uses DP internally but converts to HDMI for the output) just to get an inferior interface.
- askura 3y ago
  Honestly, it's going to be one of those things I champion now whenever it comes up in conversation haha. Very solid points.

tshaddox 3y ago

> However, I’d like to tell you that you probably should pay more attention to DisplayPort – it’s an interface powerful in a way that we haven’t seen before. Lines like that really show just how long it can take for standards to get on the radar of mainstream tech culture. I remember hearing about and being excited about DisplayPort's move to packetized digital video in college in 2008, and seeing the first Macs with MiniDisplay port later that year (or perhaps it was in 2009)! I was actually under the impression that it has been well-known and commonplace for hobbyist and enthusiast PCs for well over 10 years, but I'm probably wrong about that!

hot_gril 3y ago
That, and a similar line might've been said about FireWire, which didn't really make it.
- dylan604 3y ago
  Maybe I agree with that, but I also know that firewire helped usher in the digital video era. It allowed the transition from tape based acquisition when media cards were prohibitively expensive. Audio/Video/Deck control all down one single cable straight from the camera to the computer was what really kicked the prosumer market into being able to lean closer to pro than consumer. Now that media cards are actually affordable, that does seem like ancient history. I could see how you might think of firewire as a failure if you're looking at it as a USB type transition, but for the camera/video professions, it served a very good purpose even if short lived
  - pdmccormick 3y ago
    I once purchased a FireWire multi-channel audio interface with the express intent of reverse engineering the protocol in order to add Linux support. I purchased a specialized PCI card that was intentionally non-standard (not OHCI 1394) but could snoop and capture traffic between a device and a host. I chipped away at deciphering a register map for awhile, but eventually better USB audio devices came along that had more driver support. Still trying to do the same sort of thing though with some audio related USB and Ethernet/IP devices so I guess I never really gave up the idea in my heart!

hooverd 3y ago

For a brief moment, being able to daisy-chain displays was so cool. Now it feels like we've regressed to wrangling HDMI cables out of a USB-C hub.

TazeTSchnitzel 3y ago

The amazing thing about DVI, and by extension HDMI, is that it's just VGA but digital, with all the timing and synchronisation complexity that implies. Recall that DVI can have both an analog (VGA/DVI-A) and digital (DVI-D) signal in the same cable. They aren't independent; they share some pins and have the same timing. You could have made a CRT monitor that used DVI-D just by adding a DAC, though I'm not sure if anyone ever did. DisplayPort does away with all that legacy. I assume the hardware to implement it is much simpler and more reliable.

pavlov 3y ago
I was guessing that the oddly beautiful 17” Apple CRT Studio Display [1] from 2000 might have been a CRT that used a digital signal cable because it had the short-lived Apple Display Connector, but apparently ADC carried analog too. [1] https://everymac.com/monitors/apple/studio_cinema/specs/apple_studio_display_17_cl.html https://everymac.com/monitors/apple/studio_cinema/specs/appl...
- ShadowBanThis01 3y ago
  The ADC carried power, too, which is why Apple went with it.
MisterTea 3y ago
> You could have made a CRT monitor that used DVI-D just by adding a DAC, though I'm not sure if anyone ever did. From memory IBM offered a crt with DVI.
- thereddaikon 3y ago
  Plenty did but they were usually DVI-A or DVI-I
madars 3y ago
This also has side-channel implications, and is a reason why eDP is recommended in voting applications. https://www.eerstekamer.nl/nonav/overig/20160428/richtlijnen_ter_voorkoming_van/document https://www.eerstekamer.nl/nonav/overig/20160428/richtlijnen... >DisplayPort uses a scrambler as part of its line encoding in order to flatten the Fourier spectrum of its emissions and suppress spectral peaks caused by particular image contents. This reduces the chances of any particular image content causing a problem spectral peak during SDIP-27 and EMI spectrum measurements. According to the standard, the scrambler reduces spectral peaks by about 7 dB. As a side effect, the scrambler also makes it far more difficult, probably even impractical, for an attacker to reconstruct any information about the displayed image from the DisplayPort emissions. [..] DisplayPort uses a small number of fixed bit rates, independent of the video mode used. Unlike with most other digital interfaces, video data is transmitted in data packets with header and padding bytes, and not continuously with a television-like timing. As a result, DisplayPort cables are not a common source of van-Eckstyle video emanations and this again will make it very hard for an eavesdropper to synchronize to the transmitted data. Speaking of which: how does one force HDCP (say, in Linux)? That would transform this technology from a DRM nuisance (strippers easily available on AliExpress) into a Van Eck-countermeasure.

spearman 3y ago

> A carefully shaped money-backed lever over the market is absolutely part of reason you never see DisplayPort inputs on consumer TVs, where HDMI group reigns supreme What does this actually mean?

green-salt 3y ago
HDMI is licensed, Displayport doesn't need one. I'm sure there's money changing hands in the TV sector of most display manufacturers.

shmerl 3y ago

> Plus, It’s Not HDMI This. HDMI and its cartel that profits from its patents are super annoying.

chx 3y ago

> However, if you don’t need the full bandwidth that four lanes can give you, a DP link can consist of only one or two main lanes resulting in two This is how many USB C docks operate. The USB C connector also has four high speed lanes and there's a mode where two are assigned to carry DisplayPort data and two are assigned to be TX and RX respectively for USB. Until DP 1.4 appeared, this meant you were quite limited in display resolution if you didn't have Thunderbolt and wanted faster than 480mbps data speed. With DP 1.3, two HBR3 lanes can carry 12.96 Gbit/s which is almost exacly the requirement for 4k @ 60Hz at 12.54 Gbit/s. DP 1.4 adds compression on top of this. One more beauty of DisplayPort is it's point to point so it's entirely possible your USB C hub will carry the display data from the host to the hub as compressed HBR3 data over two lanes and then hand it out to two monitors over four uncompressed HBR2 lanes to each so a modern USB C hub can, without Thunderbolt, drive two 4k @60Hz monitors and still provide multiple gigabit speed data. It's a very neat trick. This needs full DisplayPort 1.4 support including DSC in the host, for integrated GPUs in laptop CPUs this means AMD Ryzen 4000 and newer or Intel Tiger Lake and newer (older laptops with discrete GPUs might have had it, too). Handy tip: if your hub is DP 1.4 and drives multiple monitors then it's most likely using a Synaptics MST hub to do this (almost all non-Thunderbolt ones do and many Thunderbolt ones as well) and Synaptics provides a very very little known diagnostics tool called vmmdptool (available in the Windows Store). It doesn't replace a full DP AUX protocol analyzer of course but it's free and for that price it's really handy. This topic is dear to me because I have fixed the USB C specification related to this and allow me to be damn proud of that: it used to erroneously say the USB data speed in this mixed functionality was limited to 5gbps but it is not, the limit is 10gbps. https://superuser.com/a/1536688/41259 https://superuser.com/a/1536688/41259 Ps.: When I say Thunderbolt, I am well aware of how Thunderbolt 4 is just USB4 with optional features made mandatory. It's not relevant to the discussion at hand. Pps.: DisplayPort is the native video standard for USB C, C-DisplayPort adapters and cables are basically passive because they just need to tell the host how to configure the connector lanes. Meanwhile all USB C - HDMI cables and converters are active which constantly work on the DP signal to become HDMI. DisplayPort++ alas is not implemented with the USB C connector. For this reason if any compatibility issues arise it's always better to connect a USB C device to the DisplayPort input on a monitor. A HDMI alternate mode was defined in the past but it remained paper only and it has been declared dead this year at CES.

Sparkyte 3y ago

my argument display-port of usb-c is a better interface for flexibility and utility

Ajedi32 3y ago

> A carefully shaped money-backed lever over the market is absolutely part of reason you never see DisplayPort inputs on consumer TVs, where HDMI group reigns supreme, even if the TV might use DisplayPort internally for the display panel connection. Curious about this. Is the HDMI standards group engaging in anti-competitive behavior to prevent DisplayPort from taking over on TVs? I've always assumed it was just momentum.

msie 3y ago
I was just thinking about USB-C vs Lightning... What if the EU were to mandate HDMI over DisplayPort?
- Dr4kn 3y ago
  The EU Generally chooses the more open and cheaper alternative. They did this with phone charging, car charging and would probably do the same with display connectors. USB C is the cheaper and more capable connector
6D794163636F756 3y ago
Another key is that HDMI carries more power than display port. There are dongles for your tv that can get all the power they need from an HDMI cable. Not so far display port. When it comes to use case, display port is better when connecting a fully independent device to a display and HDMI is better for connecting a peripheral to a system
- cesarb 3y ago
  > Another key is that HDMI carries more power than display port. A quick look at Wikipedia's article for both standards shows that you're wrong: DisplayPort: 3.3 V ±10%, 500 mA HDMI: 5 V, 50 mA Which means at least 1500 mW for DisplayPort, and only 250 mW for HDMI. So no, the DisplayPort cable carries more power than the HDMI cable. And when you think about it a bit, it makes sense that DisplayPort carries more power than HDMI: one of the use cases for DisplayPort is an active converter to HDMI, which needs power for both its electronics and the HDMI cable.

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dsab 3y ago

I hate HDMI, I had many problems with this interface, in my prvious job my monitor was turning off when I was getting up from chair, same was happening in my home with differeng PC, cables and monitor. Such a thing never happend to me when I changed interface to Display Port

sylware 3y ago

Don't forget, displayport is worldwide royalty free, not hdmi (similar issue than mpeg/av1, arm|x86/risc-v, etc).

qwertox 3y ago

This is a really well written article. If you haven't bothered reading about DisplayPort because you knew VGA, somewhat knew DVI and thought that HDMI is the culmination of it all, where then DisplayPort is just some further kind of evolution, this article does a really good job at explaining how DP is very different and something new, something worth knowing about. The core sentence which made me actually read the article was "DisplayPort sends its data in packets." and does a good job at explaining what this means and how this differs from HDMI.

ben0x539 3y ago
As a habitual comments skimmer, thanks for selling me on the article. :)
zsz 3y ago
I've run into problems repeatedly when it came to DP cables. The issue is always the same: lack of enforcement and no barrier to entry allows for too many entrants, whose motives are up to consumers to discern, wasting time and money in the process. What I originally saw as a benefit of an open standard, as it turned out, was in fact a benefit (for consumers like myself) of the closed/high priced standard—which ended up costing me less, in the process. Something the original article doesn't mention regarding multi-stream (MST) is that it could be used in situations where a defined standard for a certain resolution/refresh rate didn't even exist, to still make it available. For example, the earliest 4K/60Hz monitors relied on DP 1.4's (or 1.2's? I don't remember) ability to address multiple displays, to send two signals—each to cover one half of the total screen area, i.e. 1920x2160/60Hz, for a combined total of 3840x2160/60Hz—to the same display, which that display then used to internally drive two virtual screens, added seamlessly to create 3840x2160/60Hz. At the time (around 2013 and for a while thereafter), the maximum supported in single stream configuration (or by the existing HDMI standard at the time)_was 3840x2160/30Hz. You'd think this would be a point in favor of DP—which is certainly what I assumed, at the time. Unfortunately it soon became obvious that because there was no enforcement of DP compatibility—of claiming to support up to a certain version of DP fully, in other words—this meant that most cable manufacturers felt no compunction about lying shamelessly, claiming to support e.g. the 1.2 or 1.4 version at the time (which implied supporting its MST and bandwidth capabilities fully), while doing nothing of the sort. The lies did not stop there, by the way. If I could, I would here post a photo that I would happily take this very moment of such a DP cable—which didn't come especially cheap at the time, btw., in fact it took three days' worth of effort, a lot of handwringing and plain luck in the end (not to mention wasting money on several dud cables, each claimed to be fully compliant, on top of the additional money required) to finally purchase a cable that actually was compliant—which claimed gold plating as one of its features. Some fine gold that was, with black spots on both sides of the yellowish anodized plug, where the metal had oxidized! Why? Because, as I came to realize, the high barrier to entry created by the high licensing fee of the HDMI group also acts to keep away a bunch of unscrupulous manufacturers, which is purely a benefit to consumers! In addition, I've never had problems with regular size HDMI plugs—in particular, with removing them. I can't say the same when it comes to DP (especially full sized), which frequently (by design?) have a button that needs to be pushed in to release a lock that holds the plug in place. The problem is, too many times it's very difficult, if not impossible, to push down this button. Worse yet is the ambiguity that this creates: is the button fullly depressed? Is it stuck? Am I getting ready to rip out, or at least damage the underlying hardware, or even just the cable itself? These are thoughts I've had nearly every time while trying to unplug a DP cable, while HDMI (at least the standard size) slides out smoothly, as nothing is put in place to hinder this. In addition, this works well time after time, meaning there is no mechanical fatigue like with mini- and mico-USB. I can appreciate the idea that DP, when used internally (e.g. in laptops, where any shortcoming would directly reflect on the manufacturer of that laptop), or embedded within another standard, is a great idea, where its low barrier to entry /can be/ (as long as the savings are passed on, that is) a benefit to consumers. However, to claim the same in all applications is simply not supported by the real life outcome of either implementation philosophy.

cat_plus_plus 3y ago

Maybe it is, but I also want audio, so the point is moot.

goombacloud 3y ago
Audio is covered as well, as written in the article, I recommend reading it.

rbanffy 3y ago

I was very disappointed that HDMI transfers a constant bit-rate stream of pixels - VGA, but digital. I expected that, given most display devices can at least hold a full frame in-memory, that the stream could be limited to the parts of the image that changes, allowing higher frame rates when less than the full frame changes. That, and generating a signal could be much simpler than bit-banging on a DAC.

amelius 3y ago

Can we please get monitors that can find their signal within 100ms? Can we please get monitors that communicate their orientation (portrait/landscape etc.) to the computer?

jwells89 3y ago
The Apple Studio Display autodetects rotation and lets the connected computer know so it can adjust the picture accordingly, but it connects over Thunderbolt. It should be possible for monitors to do this over USB-C too, but I’m not sure about plain DisplayPort or HDMI.
- gsich 3y ago
  I2C (Aux) could do this.
- theodric 3y ago
  sigh Ok FINE I will move the goalpost I want all that in a monitor that doesn't cost more than a typical modal monthly income in Europe
  - mickelsen 3y ago
    Not Europe but Latin America, still even taking the US into account... man, the monitor market is so bad! Mass items still stuck in low resolutions, 4k goes way up, and not so many options. I mean I get it's not the TV market, but it does feel more niche compared to 10 years ago. The earliest used iMacs with 5K displays seem consistent options on the affordable side tho, and better than test-driving a possible lemon from DELL/HP/Spectre or a middle range panel from Samsung/LG.
- deergomoo 3y ago
  > it connects over Thunderbolt Not exclusively—it supports regular DP Alt Mode, though no idea if those advanced features also work.
deergomoo 3y ago

LelouBil 3y ago

A friend of mine had problems with his monitor, it would go into standby randomly when running certain games. I asked him for details about his setup and I was pretty confused when he said the connector at the back of his monitor had screws but I saw the Nvidia control panel reporting HDMI. Turns out he was using an HDMI to VGA adapter ! (GPU was outputting HDMI and screen consumed VGA). I just told him to go buy a display port cable (since his GPU and monitor both had it) and he had no problem since. Does anyone have insight about why the adapter could cause monitor standby in certain games ? It is really a peculiar issue.

tormeh 3y ago
Huh, I have the same issue with pure HDMI. No clue what the reason is.

nyanpasu64 3y ago

> If you see a DisplayPort interface on your board where you’d usually expect HDMI, that might just be because the company decided to avoid HDMI’s per-device royalties, and do firmly believe that this is a good thing. Wikipedia says DP 1.3 requires "mandatory Dual-mode for DVI and HDMI adapters". Does this mean that all DP 1.3 ports must output HDMI (and presumably pay HDMI licensing fees) as well?

somat 3y ago

The article missed the most important advantage of display port over hdmi, you can get locking connectors. I joke of course, but of the two standards bodies vesa always feels like they were less interested in playing the drm game and more interested in making a useful standard.

justusthane 3y ago
It’s mentioned towards the beginning: > Physically, desktop/laptop DisplayPort outputs come in two flavors – full-size DisplayPort, known for its latches that keep the cable in no matter what, and miniDisplayPort But yeah, the latches are great.

uglycoyote 3y ago

in my experience HDMI works better. I have had Dell 4K monitors both at my home and my work, on three different PCs all have the exact same issue: with DisplayPort I can't get more that 30hz and the mouse is so delayed that it is practically unusable. I almost sent the first monitor back, but when I decided to try the supposedly-inferior HDMI I had no trouble driving it at 60hz and the mouse movement feels buttery smooth (no latency). it's not a case of a weak video card... my card at work easily drives two of these 4K screens at 60 hz over HDMI but for some reason can't drive a single 4K monitor at more than 30 on DisplayPort. what's up with that?

nathants 3y ago

1440p 240hz is currently where it tops out. to be fair, this is a fantastic format.

fake-name 3y ago

I strongly disagree with the basic thesis of this article. HDMI is better then displayport. DVI is better then HDMI. USB-C is a complete disaster (particularly when trying to tunnel displayport). I have an ongoing hypothesis that the general robustness and pleasantness-of-use of a computer interface which will be implemented by multiple separate vendors is inversely proportional to it's complexity. As the interface protocol gets more complicated, it inevitably winds up with progressively more terrible implementations. As you add more vendors implementing the same protocol, or more features to the same protocol, the likelihood of two vendors or two implementations by the same vendor finding a corner case where they fail to interoperate properly approaches 1. I use dell laptops at work. Dell cannot get their own laptops to tunnel displayport over USB-C reliably to their own dell branded docks. Additionally, if you have an nvidia GPU, certain displayport errors will BSOD the entire computer. *Yes, plugging in a slightly misbehaving display can crash your computer entirely*. Displayport is a nightmare from the consumer's perspective. Will two displayport devices properly negotiate <feature>? Who knows?

rustybolt 3y ago

Praise displayport all day if you want, but the connector sucks and the protocol is too complicated (protip: when something in IT is called "powerful" you probably want to steer clear of it). It is much more convenient and practical to have data streams like VGA and DVI have.

phkahler 3y ago

They specifically mention 3 distinct DP connectors - standard, mini, USB-C - plus a bunch of Apple versions of them. That's NOT a feature and is exactly why I prefer HDMI. I don't care about most DP capabilities, I just want to plug in my stuff and have it work. I use 55" 4k TV for a monitor and it works, even with the open source AMD driver. I saw nothing in TFA to make me think DP would benefit me, even if some technical details are better.

dawidpotocki 3y ago
But, HDMI has multiple connectors too. HDMI, Mini HDMI, Micro HDMI, USB HDMI Alt-mode and there are also some less popular ones.

mensetmanusman 3y ago

Our work went DP on all laptops years ago but then didn't add adapters to the projectors or TVs, so everyone complained and then the newest laptops are back to hdmi and usb. Be smart people!

svlasov 3y ago

Is there an affordable 4-port DisplayPort 1.4 switch? How are they almost 10x more expensive than HDMI variants? Paying 500€ for a KVM box is not justifiable, I only want to avoid physically re-plugging the cables.

djmips 3y ago

Even the latest consoles like XBox Series X and PS5 have HDMI only outputs!

Dwedit 3y ago

So if HDMI is so restricted with NDAs, how is DisplayPort allowed to have a documented compatibility mode for it?

unstatusthequo 3y ago

Good and interesting video to explain the version diffs in spec: https://www.youtube.com/watch?v=Vn2vdQZhs0w&ab_channel=LinusTechTips https://www.youtube.com/watch?v=Vn2vdQZhs0w&ab_channel=Linus... And even better, a calculator based on your monitor capabilities that helps you choose: https://linustechtips.com/topic/729232-guide-to-display-cables-adapters-v2/ https://linustechtips.com/topic/729232-guide-to-display-cabl... I ended up with a $15 2.0 10 foot cable from Monoprice. Fit my ultra wide Samsung G9 pixel pushing needs just fine.

corajoe 3y ago

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