16 ms·

The Confusing World of USB

253 points by guiambros 6y ago

royjacobs 6y ago
It cannot be emphasized enough how much the recent USB specifications are dropping the ball. I wouldn't mind paying a small premium just for a guarantee that things will Just Work when I connect them. Instead, USB device manufacturers want to cost optimize everything, which probably forced the standard to become so Byzantine. Understandable from a manufacturer's point of view, but terrible from an end user perspective.
- dwaite 6y ago
  I blame a combination of poor enforcement of trademarks and a desire to let people support the latest specifications with the cheapest possible build cost. The poor enforcement of trademarks being - that there should not be a plethora of things claiming to be USB which are not spec compliant, nor should people be using names like "USB 3.2 Gen 1x1" vs the marketing name "Superspeed USB". You also see this poor enforcement with other organizations, such as DisplayPort vs DisplayLink. This spills over to problems with cabling, such as how much wattage is supported for power delivery or what speed data transfer is available. Oddly Intel is the one stepping up here with Thunderbolt 4, because it is now more of a certification than a specification.
  - alacombe 6y ago
    You can't blame the lack of "enforcement" to be the cause of the ills created by bad standards. I'm fairly certain that 2 official certified USB-3 cables can brick devices even though the physical form factor is the same. Relying on cables internals for function is just as stupid as can be.
    - eigenvector 6y ago
      If you think USB is bad, try looking at all the various things that can be connected together with M.2 slots vs. the pairs of devices that will actually work together despite having the same slot. I have a degree in electrical engineering and after years I only just realized that there are actually PCIe M.2 storage devices that only support AHCI mode not NVMe.
      - wtallis 6y ago
        > I have a degree in electrical engineering and after years I only just realized that there are actually PCIe M.2 storage devices that only support AHCI mode not NVMe. To be fair, there were only a handful of those really early on when M.2 was just getting started and OS/BIOS support for NVMe wasn't universal yet. And hardly any of them were released as retail products; they were mostly OEM-only drives. All of those drives went out of production 3-4 years before the first host devices that require NVMe and can't work with AHCI started to show up: USB to NVMe bridge chips for external enclosures. So if you haven't encountered an AHCI M.2 SSD yet, you probably never will and knowing about them is just an obscure historical curiosity.
    - andromeduck 6y ago
      I think USB-C would have been so much better if the CC system were saner - for example we could have had a shift uart like register based api: - Host queries some property and each cable along the way appends their value to that message and passives it along. - The endpoints either loopback if they're the new standard or pull down the pins if they're USB-2 only. - It follows that if no message makes it back then we're limited to USB 2.0 and if a message does make it back, we can query/configure all elements along the path of connections. Right now this is impossible which makes it impossible to detect if there is a non 50v tolerant hubs between two hubs. - The programming/hw implementation for PD and alternate mode would also be non-insane in this model. Currently PD requires stupidly complex state machines, op amps, resistor banks or some autonomous IC to pull off and there are so many screwups because it's such an obtuse standard. - Supporting alternate modes, and providing more diagnostic information would be much easier. There should have only been 2 passive cable types - 2.0+PD and USB 3 gen 1 - everything else should require a smart tag on the chip.
      - Pet_Ant 6y ago
        > CC system What does "CC" stand for?
        InitialLastName 6y ago
        Configuration Channel There are an added pair of pins/single wire in USB-C cables that allow the devices to a) detect the orientation of the plug and b) do extended power negotiation for the increased power capabilities of USB-C.
      - ethbr0 6y ago
        This so much. The current USB @&$#-up seems to be the result of "EEs try to expand line-level encoding to create an API." This should all be solved at the negotiation layer, even if that needs to be made more complex, so that the remaining components can be simpler and reasonably-behaved. Instead, we got something that allows each device to be a bit more electrically simple, at the cost of ballooning complexity for the ultimate use case. USB-IF took their eye off the ball, and wrote a spec for manufacturers, without thinking about the consequences to consumers. At some point, it's a value trade-off between {working product for use cases} and {+$2 on BoM}.
- etrabroline 6y ago
  >USB device manufacturers want to cost optimize everything, which probably forced the standard to become so Byzantine As Intel loses its raw CPU performance advantage, it's new marketing materials promote "features" and "convenience". Practically speaking, USB is defined by Intel, and it is making a visible choice to allow itself a position in the market for Thunderbolt 4 by making some USB4 features optional so they can include them in TB 4, and adding other small minimum performance guarantees and hoping that is enough to sell TB 4 chips to high-end AMD motherboard makers, which in turn makes their own CPUs (with built-in thunderbolt 4) more price competitive. It is a sound business plan, but not in the best interest of consumers.
  - selfhoster11 6y ago
    > It is a sound business plan, but not in the best interest of consumers. The fate of a universal lingua franca connector is too important to be left to just one company. Why is it still being defined by Intel rather than a panel?
    - dijit 6y ago
      It isn’t just Intel, there is the non-profit “USB implementers forum” (or, USB-IF) which oversees the specification. Intel, Microsoft, Apple and even HP are notable members. https://en.wikipedia.org/wiki/USB_Implementers_Forum https://en.wikipedia.org/wiki/USB_Implementers_Forum
- alacombe 6y ago
  > It cannot be emphasized enough how much the recent USB specifications are dropping the ball. This outcome was pretty obvious, it's literally in the name of the damn thing: UNIVERSAL Serial Bus. The only way to achive that is to lower yourself to the lower common denominator.
  - royjacobs 6y ago
    But that's the point, right? For a manufacturer "universal" means the lowest common denominator whereas for an end user "universal" means...well, universal.
    - alacombe 6y ago
      ... as long as there is no confusion possible for the end-user.
- DrBazza 6y ago
  I lived through the pre-USB world, and things were even more "fun". In all seriousness though, the current state of a USB is ridiculous. My wife innocently asked me why her USB C phone isn't triggering Android Auto in the car, and straight away you know it's because she bought a USB C power-only cable without knowing the difference. Nice.
  - bzb6 6y ago
    Aren’t power-only cables a security feature?
    - zdkl 6y ago
      They are, and frankly that they need to exist is the single most egregious example of why USB isn't what I need it to be. What (I'm surprised) I haven't seen is a male-to-female adapter with a switch on it that physically kills the data tx lines.
      - AussieWog93 6y ago
        A device very similar to the one you described exists: the aptly named "USB Condom"!
        lasereyes136 6y ago
        Indeed, I have two of them. They don't always work correctly. Meaning they don't always charge depending on the device and cable you plug into them.
        SAI_Peregrinus 6y ago
        I've got a (USB2) power monitor that includes a chip (just an STM8L051F3 microcontroller) to manage power negotiation and keep data disconnected. So it negotiates power with host and device separately, without ever needing to connect the data lines from host to device directly. I expect there are or will be versions for USB 3.<whatever I've lost track>.
- qppo 6y ago
  Consumers want one cable and connector for all devices regardless of the ridiculous notion that all devices should have similar enough electrical requirements that they could use one cable. The result is USB.
- gumby 6y ago
  It's no accident that the USB group is called the "USBIF" -- "USB Implementor's Forum". This is different from, say, the C++ standards committee which is a combo of compiler & std library developers (i.e. implementors!), enthusiasts, and some who are best referred to as "users". Not a criticism of the USBIF* just pointing out the motivations to underline your point. * BTW I have plenty of criticism, this just happens not to be an example.
boguscoder 6y ago
If author ever reads comments here: date in the post says 2020 but is from 2021, right?..
- fabiensanglard 6y ago
  It looks a lot like 2020 so far but you are nonetheless correct. Merci ;) !
  - raphman 6y ago
    Typo: > This allows 40k60 on two lanes
deleted 6y ago
[deleted]
SV_BubbleTime 6y ago
Wait, did he get the wiring wrong? I was under the impression that cables with power delivery used two pairs of power and ground (upto 20V iirc). https://images.anandtech.com/doci/11667/usbtypec-pins.png https://images.anandtech.com/doci/11667/usbtypec-pins.png
- Kliment 6y ago
  Cables with power delivery have a single wire for power negotiation (CC) and a single pair of power/ground. The connector, on the other hand, has two CC pins (one of which is connected to the CC wire, and the other is not) and two pairs of power/ground. It also has a few other things - a pair of wires for weird low speed uses (SBU) and an additional pin for supplying power to the cable in case the cable itself has a chip in it.
morning_gelato 6y ago
I thought it went: USB 3.0 (5Gbps) == USB 3.1 Gen 1 == USB 3.2 1x1, and USB 3.1 Gen 2 (10Gbps) == USB Gen 3.2 2x1. Yet the article states: >Accordingly "USB 3.1 Gen 2" became "USB 3.2 Gen 1x1" and "USB 3.1 Gen 1" was renamed "USB 3.2 Gen 2x1". Either way, this article gets the point across that USB has turned into a complete mess.
- Dagonfly 6y ago
  Yeah, the author accidentally swapped the new names. The rebrandings never changed the "Gen X" part. That's what I don't understand: Why go with both minor versions and the Gen's in a single name? They could have just retroactively rebranded USB 3.0 to USB3 Gen1, and then went USB3 Gen2, USB3 Gen3 for the 3.1 and 3.2 specs (2×2 is another mess [1]). Tech people would have understood that the specs are 0-indexed and the marketing names (GenX) are 1-indexed. Consumers would only see the Gen on ports, cables and devices. Still, I don't even understand why hiding the raw speed number from consumers is so important: Short Numbers are always better than vagely similar marketing names: - USB3 (5Gb) - USB3 (10Gb) - USB3 (20Gb) - USB3 (40Gb) or (2×20Gb) Done. [1] The final page of this Anandtech article is pretty spot on about Gen2×2: https://www.anandtech.com/show/16133/usb-32-gen-2x2-state-of-the-ecosystem-review/8 https://www.anandtech.com/show/16133/usb-32-gen-2x2-state-of...
Traubenfuchs 6y ago
So Thunderbolt 4 devices and cables always have all USB features? Just buy a thunderbolt 4 hub?
- outadoc 6y ago
  They're prohibitively expensive.
  - izacus 6y ago
    Well, that's the side effect of demanding 40Gbps capable cables just to charge your headphones.
    - MichaelZuo 6y ago
      Yup, peace of mind in the USB world apparently comes at a large cost.
      - secabeen 6y ago
        Yeah, people want to have their cake and eat it too. They want every device to support and pass through every modern feature, the highest speeds, and the fastest charging, but they also only want to pay less than $5 per USB interface, and they want full backwards compatibility with all historic devices. It's just not possible, we are pushing the boundaries of what's possible physically. Apple solves the problem by over-provisioning everything; but as you note, Apple products are expensive. Additionally, there are hundreds of manufactures making equipment that uses the USB ports, but which don't follow the specs beyond what's needed to "make it work", and they can't be stopped through legal or trademark enforcement as they're largely-foreign, and they just fold and re-appear as a different company if ever challenged legally.
- DougBTX 6y ago
  Seems like a well worn path: either pay more for the full-featured option, pay less for the minimal-feature option, or do the research to find the cheapest option which does everything you need.
jerome-jh 6y ago
I would go against the introduction (USB is simple and reliable): it took about 10 years to stabilize in Windows. During that time serial (RS232) devices were more reliable than USB ones.
- dfox 6y ago
  That is mostly an issue with Windows' device driver architecture and not with USB itself. Windows tries hard to assign unique and persistent internal "name" to every device it has even seen, the resulting device record then has bunch of named attributes which are used to match correct driver to it. In context of USB there are two problems with this otherwise pretty clever and universal design: there are pretty common edge cases when the "unique and persistent" name is neither and then there are drivers (including drivers supplied by MS as part of windows itself) that match on wrong attributes.
sneak 6y ago
I still think it's all worth it because we have a single, reversible port for 5V, or usb2/3 (gen1). The confusion created by PD/3.1/dp/hdmi/tb/etc is mostly irrelevant to me, and I think the clusterfuck there is real but overblown (so long as pd devices will charge slowly from normal 5V c ports/cables, and usb3.whatever will fall back to usb2). I can charge my travel router, dji gimbal, gopro, android phone, ipad, and macbook pro (albeit slowly) from the same cheap cables. Neewer battery chargers are now dual micro/c, too. Even if it were just a 5v connector it would be a win.
- eigenvector 6y ago
  It's not just 5V, though. PD can supply up to 20 V and poor implementation can brick 5 V devices by supplying the wrong voltage.
  - sneak 6y ago
    It could be argued that a supposed PD device that provides 20V without negotiation isn't just a "poor implementation" but is in fact not PD at all. The fact that I can wire up a 220VAC etherkiller with a USB-C port on the end is not a failing of the USB spec or in any way the fault of the USB-IF.
    - Dylan16807 6y ago
      I believe there was a charger that would negotiate a higher voltage, but didn't notice when you unplugged the far end of the cable and kept the near end plugged in. Then you could attach a new device and possibly fry it. I'd file that under "poor implementation".
  - stragies 6y ago
    Depending on your job description, you might see that as a feature .... BOFH: "Oh, the user connected an unauthorized USB device; let's see, how it handles 20V"
nousermane 6y ago
I'd be really curious to understand the origin of this "USB required 3 tries to plug in" thing. It seem this is something everybody agrees with nowadays, but was it always like that? After all, USB-A plug has a prominent logo (distinguishable both on sight and by touch) that identifies up-side. It should be dead-simple to do, no? What went wrong? - Did some laptop manufacturer mount USB-A receptacle upside-down? - Or was that micro-B that trigger this? (for example Samsung/Nexus S and LG/Nexus 4/5 have micro-B receptacle upside-down relative to one another) - General feeling of inferiority from Apple's Lightning plug? - Something else altogether?
- MartijnBraam 6y ago
  I have ~2 devices with upside down usb ports, I usually look for the holes in the connector instead of the logo to see which side is up. The major feature of usb-c isn't that it's bi-directional as in "you don't have to try 3 times", it's bi-directional as in "it's both an host and perpipheral port" but somehow everyone seems to forget that. That's why it's a C connector, it's both A and B
  - deleted 6y ago
    [deleted]
- jleahy 6y ago
  Personally I never noticed that there is a logo, and that logo means up. And I’ve plugged in a lot of USB cables in my time, and even read parts of the USB spec in order to implement USB. Maybe I’m just a moron though.
- aliceryhl 6y ago
  I never realized that the logo means "up". I think that is far from well-known information.
  - aargh_aargh 6y ago
    Anecdata: My mouse is connected to my PC in the front, so I just reached to check the logo and I'm feeling a logo on both sides of the connector. So I unplug it to check and it has the USB logo on the top and the Genius logo on the bottom. C'est génial! <facepalm>
mschuster91 6y ago
> Yes it favors something proprietary over something open since Thunderbolt is 100% owned by Intel who also produce all controllers. Not entirely. There are third party TB controllers by now, the problem is they're heavily guarded by NDAs.
- neallindsay 6y ago
  As far as I know, only Apple is producing their own Thunderbolt 4 controllers so far. Also, I heard that Thunderbolt 4 is the same as Thunderbolt 3, except all the optional features from 3 are required in 4. This interview seems relevant: https://www.youtube.com/watch?v=lnSMbgndFHo&t=2m3s&feature=youtu.be https://www.youtube.com/watch?v=lnSMbgndFHo&t=2m3s&feature=y...
  - sq_ 6y ago
    Hopefully we'll see more Thunderbolt 4 silicon from different manufacturers as USB4 rolls out. Seems like we'll probably see that over the next year or two if it's going to happen.
amelius 6y ago
Is anyone working on a sane replacement for USB?
- deleted 6y ago
  [deleted]
- izacus 6y ago
  The secret here is that the "messiness" of USB is what makes it so popular and usable across all types of hardware. It can be very cheap, very fast, very powerful and still be compatible with most* devices. Any other standard trying to fix one of the aspects will drop the ball on the others - e.g. see Apple's attempts at Thunderbolt 2.
  - amelius 6y ago
    RS232 was powerful and quite simple at the same time.
    - izacus 6y ago
      And incapable of most common USB use-cases even at the time. Also, "simple" has to mean something else in your world because I distinctly remember the onus of having to figure out the right baudrate, stopbit and parity bit configuration. Not to mention devices which used TTL level RS-232 and wouldn't work with other devices DESPITE having the same connector and standard. USB is a godsend compared to that.
      - ziml77 6y ago
        Plus the D-sub connectors were standard, but anything regarding their wiring was handled by different standards. So just putting connectors where they fit wasn't enough to be sure that it would actually work and could even fry one or both ends of the connection. With USB, as long as the both ends and the cable are built to spec, it's safe to mix and match. You'll just end up with the lowest common denominator of functionality.
moonbug 6y ago
Now do Bluetooth
person_of_color 6y ago
They screwed up once they allowed PCI-e over USB. SMFH.
- gibspaulding 6y ago
  Honestly, you're not wrong. It seems going back to having a separate plug for thunderbolt would solve a lot of problems. Effectively, you already need to buy special cables for it, so they might as well look different to prevent confusion.
  - Cu3PO42 6y ago
    Going back? Thunderbolt 1 and 2 were both Mini DisplayPort connectors. I don't disagree that having a seperate plug may be sensible, but all iterations of Thunderbolt so far used a pre-existing connector.
zadwang 6y ago
I just hope the USB port could be of the uniform size of that of USB 2.0, not that of USB type C. I feel small size is not convenient and mechanically weak.
- gertrunde 6y ago
  This is particularly noticeable with things like Thunderbolt docks, where knocking the cable slightly can cause connectivity to the dock to blip momentarily, which has the knock-on effect of a 5-10 second delay while everything gets straightened out again, killing display, network and any other downstream devices for teh duration.
  - cesarb 6y ago
    In my experience, this also happens often with older/worn-out USB-A ports. What's worse is that, unlike USB-C, the springs on USB-A are on the socket, so replacing the cable doesn't help.
eqvinox 6y ago
> USB-3.X cables features 8 wires. Nope... it's even more complicated. Up to "3.2 Gen 2x1" they have 8 wires, but "3.2 Gen2x2" has 12 wires. There's two pairs of RX and TX each, i.e. RX1- RX1+ RX2- RX2+ TX1- TX1+ TX2- TX2+ D- D+ PWR GND = 12. And... that's still not correct: USB-C to USB-C cables have an additional CC line which carries the Type-C extra negotiation (e.g. alt mode switch, power levels.) And just to fuck users over even more, there is a difference between a 13-pin full-function "USB 3.2 Gen2x2" cable and a 13-pin full-function Thunderbolt cable: the Thunderbolt cable reports an extra "vendor descriptor" on the Type-C negotiation channel, indicating support for TB. The cables are otherwise physically identical, but these extra bits come with a ~$15 markdown. (Oh and the PWR/GND lines can be 3A or 5A, but at this point...) The article is, however, correct in its conclusion: a "Thunderbolt" cable will always work for all USB standards. The only free variable on a TB cable is whether it does 3A or 5A for power.
- organsnyder 6y ago
  About a year ago I switched to an iPhone after being a longtime (~10 years) Android user. Last night I was at the grocery store and impulse-bought a Lightning charging cable to carry in my hiking backpack. No way I would ever have trusted a checkout-lane USB cable, but Apple's tighter controls give me a greater assurance that the cable will work well and not damage things.
  - rasz 6y ago
    >grocery store checkout-lane Lightning charging cable is how you burn your Tristar in the best case scenario, and a House if you are unlucky https://www.goodmorningamerica.com/living/story/gma-investigates-inexpensive-lightning-cables-harm-phone-54920478 https://www.goodmorningamerica.com/living/story/gma-investig... https://www.vice.com/en/article/bj34z5/why-counterfeit-lightning-cables-kill-iphones-cheap-iphone-chargers https://www.vice.com/en/article/bj34z5/why-counterfeit-light... 'Jessa Jones, owner of iPad Rehab in Honeoye Falls' cited above is a legend https://www.youtube.com/c/Mendonipadrehab/videos https://www.youtube.com/c/Mendonipadrehab/videos
    - 6y ago
rasz 6y ago
Love Fabien write-ups! > badly fragmented connector world made of Dont forget SCSI. USB killed external SCSI. >Up to that point in time, it was a good tech stack. USB 0.9 was 1995, USB 1.0 1996. Two years later we had Bill Gates getting embarrassed by Windows 98 BSOD on stage https://www.youtube.com/watch?v=IW7Rqwwth84 https://www.youtube.com/watch?v=IW7Rqwwth84. By ~2002 we ended up with 6 separate incompatible proprietary variations on micro USB. Pretty much every second Camera vendor had its won "standard". >USB-3.X cables features 8 wires .... and the other six carry data Sadly just adding even more confusion to the mix. 24 pins, up to 13 signals, 4 pairs (8 wires) dedicated to USB 3.2 alone. >Thanks to DP 1.4, the bandwidth requirement can be lowered via DSP lossless compression oh its very much lossy, Display Stream Compression (DSC) is "visually lossless" :--------) it works similar to Texture Compression, but works on blocks of lines instead of rectangles, still it does destroy information by cutting off color accuracy. At the end of the day USB is still trivial compared to Bluetooh.
emddudley 6y ago
> Accordingly "USB 3.1 Gen 2" became "USB 3.2 Gen 1x1" and "USB 3.1 Gen 1" was renamed "USB 3.2 Gen 2x1". Is this correct? It seems swapped.
mauvehaus 6y ago
And that's just the stuff that makes a good-faith effort to the specs. My wife bought me an LED light panel for Christmas so I wouldn't be so grouchy in the winter (gift for me or her: you decide). It uses a USB mini connector for a 19.whatever volt power supply. Don't plug that into your external HDD by mistake. Yes, I know USB mini is obsolete, but we still own a couple devices that use it. And the plug is stamped with the USB logo.
- citrusybread 6y ago
  I have that exact same light panel. I have no idea how the manufacturer got away with it -- they're not a small company at all. I also have no idea how they ever thought that was a good idea vs just using a barrel plug.
LockAndLol 6y ago
Seriously, what is going on with USB? I bought a charging cable for my phone once that supports fast charging. The connectors all fit but no fast charging? Shipped it back and bought another one - what a waste of resources. They really need to use semantic versioning and be forced to clearly display that version number on the cable or connector in a legally defined, readable size. In fact every cable type should have that. I recently bought a 2K 144Hz screen and could get the display manager to set 144Hz. Then I looked up the standard and found out HDMI 1 doesn't support 144Hz but HDMI 2 does. Not a single cable in my house has the version number written anywhere and I had to try them out until I got the right one. What I would really appreciate is: Cable X not compatible with Cable Y --> different major versions and completely improved specs, power requirements, AND different shape Cable X.X is compatible with Cable X.Y but has different functionalities --> same major version, different minor version, same shape. Easily understandable by users "First thing I see is a big X, it fits with whatever I'm trying to connect with, it should work". If it doesn't then they can look closer and go "ooh.. the small Y is different. I should get Y or Y+n". That's it.
qwerty456127 6y ago
It was perfectly reasonable to allow partial implementations among peripherals and host controllers to let cheap and simple devices exist. But allowing different cables was a mistake. Every single USB-C cable manufactured today must be required to support Thunderbolt, high-current charging and everything.
Koshkin 6y ago
La USB ?... mais c'est très simple ! http://www.usbmadesimple.co.uk/ http://www.usbmadesimple.co.uk/

253 points by guiambros 6y ago

It cannot be emphasized enough how much the recent USB specifications are dropping the ball. I wouldn't mind paying a small premium just for a guarantee that things will Just Work when I connect them. Instead, USB device manufacturers want to cost optimize everything, which probably forced the standard to become so Byzantine. Understandable from a manufacturer's point of view, but terrible from an end user perspective.

dwaite 6y ago
I blame a combination of poor enforcement of trademarks and a desire to let people support the latest specifications with the cheapest possible build cost. The poor enforcement of trademarks being - that there should not be a plethora of things claiming to be USB which are not spec compliant, nor should people be using names like "USB 3.2 Gen 1x1" vs the marketing name "Superspeed USB". You also see this poor enforcement with other organizations, such as DisplayPort vs DisplayLink. This spills over to problems with cabling, such as how much wattage is supported for power delivery or what speed data transfer is available. Oddly Intel is the one stepping up here with Thunderbolt 4, because it is now more of a certification than a specification.
- alacombe 6y ago
  You can't blame the lack of "enforcement" to be the cause of the ills created by bad standards. I'm fairly certain that 2 official certified USB-3 cables can brick devices even though the physical form factor is the same. Relying on cables internals for function is just as stupid as can be.
  - eigenvector 6y ago
    If you think USB is bad, try looking at all the various things that can be connected together with M.2 slots vs. the pairs of devices that will actually work together despite having the same slot. I have a degree in electrical engineering and after years I only just realized that there are actually PCIe M.2 storage devices that only support AHCI mode not NVMe.
    - wtallis 6y ago
      > I have a degree in electrical engineering and after years I only just realized that there are actually PCIe M.2 storage devices that only support AHCI mode not NVMe. To be fair, there were only a handful of those really early on when M.2 was just getting started and OS/BIOS support for NVMe wasn't universal yet. And hardly any of them were released as retail products; they were mostly OEM-only drives. All of those drives went out of production 3-4 years before the first host devices that require NVMe and can't work with AHCI started to show up: USB to NVMe bridge chips for external enclosures. So if you haven't encountered an AHCI M.2 SSD yet, you probably never will and knowing about them is just an obscure historical curiosity.
  - andromeduck 6y ago
    I think USB-C would have been so much better if the CC system were saner - for example we could have had a shift uart like register based api: - Host queries some property and each cable along the way appends their value to that message and passives it along. - The endpoints either loopback if they're the new standard or pull down the pins if they're USB-2 only. - It follows that if no message makes it back then we're limited to USB 2.0 and if a message does make it back, we can query/configure all elements along the path of connections. Right now this is impossible which makes it impossible to detect if there is a non 50v tolerant hubs between two hubs. - The programming/hw implementation for PD and alternate mode would also be non-insane in this model. Currently PD requires stupidly complex state machines, op amps, resistor banks or some autonomous IC to pull off and there are so many screwups because it's such an obtuse standard. - Supporting alternate modes, and providing more diagnostic information would be much easier. There should have only been 2 passive cable types - 2.0+PD and USB 3 gen 1 - everything else should require a smart tag on the chip.
    - Pet_Ant 6y ago
      > CC system What does "CC" stand for?
      - InitialLastName 6y ago
        Configuration Channel There are an added pair of pins/single wire in USB-C cables that allow the devices to a) detect the orientation of the plug and b) do extended power negotiation for the increased power capabilities of USB-C.
    - ethbr0 6y ago
      This so much. The current USB @&$#-up seems to be the result of "EEs try to expand line-level encoding to create an API." This should all be solved at the negotiation layer, even if that needs to be made more complex, so that the remaining components can be simpler and reasonably-behaved. Instead, we got something that allows each device to be a bit more electrically simple, at the cost of ballooning complexity for the ultimate use case. USB-IF took their eye off the ball, and wrote a spec for manufacturers, without thinking about the consequences to consumers. At some point, it's a value trade-off between {working product for use cases} and {+$2 on BoM}.
etrabroline 6y ago
>USB device manufacturers want to cost optimize everything, which probably forced the standard to become so Byzantine As Intel loses its raw CPU performance advantage, it's new marketing materials promote "features" and "convenience". Practically speaking, USB is defined by Intel, and it is making a visible choice to allow itself a position in the market for Thunderbolt 4 by making some USB4 features optional so they can include them in TB 4, and adding other small minimum performance guarantees and hoping that is enough to sell TB 4 chips to high-end AMD motherboard makers, which in turn makes their own CPUs (with built-in thunderbolt 4) more price competitive. It is a sound business plan, but not in the best interest of consumers.
- selfhoster11 6y ago
  > It is a sound business plan, but not in the best interest of consumers. The fate of a universal lingua franca connector is too important to be left to just one company. Why is it still being defined by Intel rather than a panel?
  - dijit 6y ago
    It isn’t just Intel, there is the non-profit “USB implementers forum” (or, USB-IF) which oversees the specification. Intel, Microsoft, Apple and even HP are notable members. https://en.wikipedia.org/wiki/USB_Implementers_Forum https://en.wikipedia.org/wiki/USB_Implementers_Forum
alacombe 6y ago
> It cannot be emphasized enough how much the recent USB specifications are dropping the ball. This outcome was pretty obvious, it's literally in the name of the damn thing: UNIVERSAL Serial Bus. The only way to achive that is to lower yourself to the lower common denominator.
- royjacobs 6y ago
  But that's the point, right? For a manufacturer "universal" means the lowest common denominator whereas for an end user "universal" means...well, universal.
  - alacombe 6y ago
    ... as long as there is no confusion possible for the end-user.
DrBazza 6y ago
I lived through the pre-USB world, and things were even more "fun". In all seriousness though, the current state of a USB is ridiculous. My wife innocently asked me why her USB C phone isn't triggering Android Auto in the car, and straight away you know it's because she bought a USB C power-only cable without knowing the difference. Nice.
- bzb6 6y ago
  Aren’t power-only cables a security feature?
  - zdkl 6y ago
    They are, and frankly that they need to exist is the single most egregious example of why USB isn't what I need it to be. What (I'm surprised) I haven't seen is a male-to-female adapter with a switch on it that physically kills the data tx lines.
    - AussieWog93 6y ago
      A device very similar to the one you described exists: the aptly named "USB Condom"!
      - lasereyes136 6y ago
        Indeed, I have two of them. They don't always work correctly. Meaning they don't always charge depending on the device and cable you plug into them.
        SAI_Peregrinus 6y ago
        I've got a (USB2) power monitor that includes a chip (just an STM8L051F3 microcontroller) to manage power negotiation and keep data disconnected. So it negotiates power with host and device separately, without ever needing to connect the data lines from host to device directly. I expect there are or will be versions for USB 3.<whatever I've lost track>.
qppo 6y ago
Consumers want one cable and connector for all devices regardless of the ridiculous notion that all devices should have similar enough electrical requirements that they could use one cable. The result is USB.
gumby 6y ago
It's no accident that the USB group is called the "USBIF" -- "USB Implementor's Forum". This is different from, say, the C++ standards committee which is a combo of compiler & std library developers (i.e. implementors!), enthusiasts, and some who are best referred to as "users". Not a criticism of the USBIF* just pointing out the motivations to underline your point. * BTW I have plenty of criticism, this just happens not to be an example.

boguscoder 6y ago

If author ever reads comments here: date in the post says 2020 but is from 2021, right?..

fabiensanglard 6y ago
It looks a lot like 2020 so far but you are nonetheless correct. Merci ;) !
- raphman 6y ago
  Typo: > This allows 40k60 on two lanes

deleted 6y ago

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SV_BubbleTime 6y ago

Wait, did he get the wiring wrong? I was under the impression that cables with power delivery used two pairs of power and ground (upto 20V iirc). https://images.anandtech.com/doci/11667/usbtypec-pins.png https://images.anandtech.com/doci/11667/usbtypec-pins.png

Kliment 6y ago
Cables with power delivery have a single wire for power negotiation (CC) and a single pair of power/ground. The connector, on the other hand, has two CC pins (one of which is connected to the CC wire, and the other is not) and two pairs of power/ground. It also has a few other things - a pair of wires for weird low speed uses (SBU) and an additional pin for supplying power to the cable in case the cable itself has a chip in it.

morning_gelato 6y ago

I thought it went: USB 3.0 (5Gbps) == USB 3.1 Gen 1 == USB 3.2 1x1, and USB 3.1 Gen 2 (10Gbps) == USB Gen 3.2 2x1. Yet the article states: >Accordingly "USB 3.1 Gen 2" became "USB 3.2 Gen 1x1" and "USB 3.1 Gen 1" was renamed "USB 3.2 Gen 2x1". Either way, this article gets the point across that USB has turned into a complete mess.

Dagonfly 6y ago
Yeah, the author accidentally swapped the new names. The rebrandings never changed the "Gen X" part. That's what I don't understand: Why go with both minor versions and the Gen's in a single name? They could have just retroactively rebranded USB 3.0 to USB3 Gen1, and then went USB3 Gen2, USB3 Gen3 for the 3.1 and 3.2 specs (2×2 is another mess [1]). Tech people would have understood that the specs are 0-indexed and the marketing names (GenX) are 1-indexed. Consumers would only see the Gen on ports, cables and devices. Still, I don't even understand why hiding the raw speed number from consumers is so important: Short Numbers are always better than vagely similar marketing names: - USB3 (5Gb) - USB3 (10Gb) - USB3 (20Gb) - USB3 (40Gb) or (2×20Gb) Done. [1] The final page of this Anandtech article is pretty spot on about Gen2×2: https://www.anandtech.com/show/16133/usb-32-gen-2x2-state-of-the-ecosystem-review/8 https://www.anandtech.com/show/16133/usb-32-gen-2x2-state-of...

Traubenfuchs 6y ago

So Thunderbolt 4 devices and cables always have all USB features? Just buy a thunderbolt 4 hub?

outadoc 6y ago
They're prohibitively expensive.
- izacus 6y ago
  Well, that's the side effect of demanding 40Gbps capable cables just to charge your headphones.
  - MichaelZuo 6y ago
    Yup, peace of mind in the USB world apparently comes at a large cost.
    - secabeen 6y ago
      Yeah, people want to have their cake and eat it too. They want every device to support and pass through every modern feature, the highest speeds, and the fastest charging, but they also only want to pay less than $5 per USB interface, and they want full backwards compatibility with all historic devices. It's just not possible, we are pushing the boundaries of what's possible physically. Apple solves the problem by over-provisioning everything; but as you note, Apple products are expensive. Additionally, there are hundreds of manufactures making equipment that uses the USB ports, but which don't follow the specs beyond what's needed to "make it work", and they can't be stopped through legal or trademark enforcement as they're largely-foreign, and they just fold and re-appear as a different company if ever challenged legally.
DougBTX 6y ago
Seems like a well worn path: either pay more for the full-featured option, pay less for the minimal-feature option, or do the research to find the cheapest option which does everything you need.

jerome-jh 6y ago

I would go against the introduction (USB is simple and reliable): it took about 10 years to stabilize in Windows. During that time serial (RS232) devices were more reliable than USB ones.

dfox 6y ago
That is mostly an issue with Windows' device driver architecture and not with USB itself. Windows tries hard to assign unique and persistent internal "name" to every device it has even seen, the resulting device record then has bunch of named attributes which are used to match correct driver to it. In context of USB there are two problems with this otherwise pretty clever and universal design: there are pretty common edge cases when the "unique and persistent" name is neither and then there are drivers (including drivers supplied by MS as part of windows itself) that match on wrong attributes.

sneak 6y ago

I still think it's all worth it because we have a single, reversible port for 5V, or usb2/3 (gen1). The confusion created by PD/3.1/dp/hdmi/tb/etc is mostly irrelevant to me, and I think the clusterfuck there is real but overblown (so long as pd devices will charge slowly from normal 5V c ports/cables, and usb3.whatever will fall back to usb2). I can charge my travel router, dji gimbal, gopro, android phone, ipad, and macbook pro (albeit slowly) from the same cheap cables. Neewer battery chargers are now dual micro/c, too. Even if it were just a 5v connector it would be a win.

eigenvector 6y ago
It's not just 5V, though. PD can supply up to 20 V and poor implementation can brick 5 V devices by supplying the wrong voltage.
- sneak 6y ago
  It could be argued that a supposed PD device that provides 20V without negotiation isn't just a "poor implementation" but is in fact not PD at all. The fact that I can wire up a 220VAC etherkiller with a USB-C port on the end is not a failing of the USB spec or in any way the fault of the USB-IF.
  - Dylan16807 6y ago
    I believe there was a charger that would negotiate a higher voltage, but didn't notice when you unplugged the far end of the cable and kept the near end plugged in. Then you could attach a new device and possibly fry it. I'd file that under "poor implementation".
- stragies 6y ago
  Depending on your job description, you might see that as a feature .... BOFH: "Oh, the user connected an unauthorized USB device; let's see, how it handles 20V"

nousermane 6y ago

I'd be really curious to understand the origin of this "USB required 3 tries to plug in" thing. It seem this is something everybody agrees with nowadays, but was it always like that? After all, USB-A plug has a prominent logo (distinguishable both on sight and by touch) that identifies up-side. It should be dead-simple to do, no? What went wrong? - Did some laptop manufacturer mount USB-A receptacle upside-down? - Or was that micro-B that trigger this? (for example Samsung/Nexus S and LG/Nexus 4/5 have micro-B receptacle upside-down relative to one another) - General feeling of inferiority from Apple's Lightning plug? - Something else altogether?

MartijnBraam 6y ago
I have ~2 devices with upside down usb ports, I usually look for the holes in the connector instead of the logo to see which side is up. The major feature of usb-c isn't that it's bi-directional as in "you don't have to try 3 times", it's bi-directional as in "it's both an host and perpipheral port" but somehow everyone seems to forget that. That's why it's a C connector, it's both A and B
- deleted 6y ago
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jleahy 6y ago
Personally I never noticed that there is a logo, and that logo means up. And I’ve plugged in a lot of USB cables in my time, and even read parts of the USB spec in order to implement USB. Maybe I’m just a moron though.
aliceryhl 6y ago
I never realized that the logo means "up". I think that is far from well-known information.
- aargh_aargh 6y ago
  Anecdata: My mouse is connected to my PC in the front, so I just reached to check the logo and I'm feeling a logo on both sides of the connector. So I unplug it to check and it has the USB logo on the top and the Genius logo on the bottom. C'est génial! <facepalm>

mschuster91 6y ago

> Yes it favors something proprietary over something open since Thunderbolt is 100% owned by Intel who also produce all controllers. Not entirely. There are third party TB controllers by now, the problem is they're heavily guarded by NDAs.

neallindsay 6y ago
As far as I know, only Apple is producing their own Thunderbolt 4 controllers so far. Also, I heard that Thunderbolt 4 is the same as Thunderbolt 3, except all the optional features from 3 are required in 4. This interview seems relevant: https://www.youtube.com/watch?v=lnSMbgndFHo&t=2m3s&feature=youtu.be https://www.youtube.com/watch?v=lnSMbgndFHo&t=2m3s&feature=y...
- sq_ 6y ago
  Hopefully we'll see more Thunderbolt 4 silicon from different manufacturers as USB4 rolls out. Seems like we'll probably see that over the next year or two if it's going to happen.

amelius 6y ago

Is anyone working on a sane replacement for USB?

deleted 6y ago
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izacus 6y ago
The secret here is that the "messiness" of USB is what makes it so popular and usable across all types of hardware. It can be very cheap, very fast, very powerful and still be compatible with most* devices. Any other standard trying to fix one of the aspects will drop the ball on the others - e.g. see Apple's attempts at Thunderbolt 2.
- amelius 6y ago
  RS232 was powerful and quite simple at the same time.
  - izacus 6y ago
    And incapable of most common USB use-cases even at the time. Also, "simple" has to mean something else in your world because I distinctly remember the onus of having to figure out the right baudrate, stopbit and parity bit configuration. Not to mention devices which used TTL level RS-232 and wouldn't work with other devices DESPITE having the same connector and standard. USB is a godsend compared to that.
    - ziml77 6y ago
      Plus the D-sub connectors were standard, but anything regarding their wiring was handled by different standards. So just putting connectors where they fit wasn't enough to be sure that it would actually work and could even fry one or both ends of the connection. With USB, as long as the both ends and the cable are built to spec, it's safe to mix and match. You'll just end up with the lowest common denominator of functionality.

moonbug 6y ago

Now do Bluetooth

person_of_color 6y ago

They screwed up once they allowed PCI-e over USB. SMFH.

gibspaulding 6y ago
Honestly, you're not wrong. It seems going back to having a separate plug for thunderbolt would solve a lot of problems. Effectively, you already need to buy special cables for it, so they might as well look different to prevent confusion.
- Cu3PO42 6y ago
  Going back? Thunderbolt 1 and 2 were both Mini DisplayPort connectors. I don't disagree that having a seperate plug may be sensible, but all iterations of Thunderbolt so far used a pre-existing connector.

zadwang 6y ago

I just hope the USB port could be of the uniform size of that of USB 2.0, not that of USB type C. I feel small size is not convenient and mechanically weak.

gertrunde 6y ago
This is particularly noticeable with things like Thunderbolt docks, where knocking the cable slightly can cause connectivity to the dock to blip momentarily, which has the knock-on effect of a 5-10 second delay while everything gets straightened out again, killing display, network and any other downstream devices for teh duration.
- cesarb 6y ago
  In my experience, this also happens often with older/worn-out USB-A ports. What's worse is that, unlike USB-C, the springs on USB-A are on the socket, so replacing the cable doesn't help.

eqvinox 6y ago

> USB-3.X cables features 8 wires. Nope... it's even more complicated. Up to "3.2 Gen 2x1" they have 8 wires, but "3.2 Gen2x2" has 12 wires. There's two pairs of RX and TX each, i.e. RX1- RX1+ RX2- RX2+ TX1- TX1+ TX2- TX2+ D- D+ PWR GND = 12. And... that's still not correct: USB-C to USB-C cables have an additional CC line which carries the Type-C extra negotiation (e.g. alt mode switch, power levels.) And just to fuck users over even more, there is a difference between a 13-pin full-function "USB 3.2 Gen2x2" cable and a 13-pin full-function Thunderbolt cable: the Thunderbolt cable reports an extra "vendor descriptor" on the Type-C negotiation channel, indicating support for TB. The cables are otherwise physically identical, but these extra bits come with a ~$15 markdown. (Oh and the PWR/GND lines can be 3A or 5A, but at this point...) The article is, however, correct in its conclusion: a "Thunderbolt" cable will always work for all USB standards. The only free variable on a TB cable is whether it does 3A or 5A for power.

organsnyder 6y ago
About a year ago I switched to an iPhone after being a longtime (~10 years) Android user. Last night I was at the grocery store and impulse-bought a Lightning charging cable to carry in my hiking backpack. No way I would ever have trusted a checkout-lane USB cable, but Apple's tighter controls give me a greater assurance that the cable will work well and not damage things.
- rasz 6y ago
  >grocery store checkout-lane Lightning charging cable is how you burn your Tristar in the best case scenario, and a House if you are unlucky https://www.goodmorningamerica.com/living/story/gma-investigates-inexpensive-lightning-cables-harm-phone-54920478 https://www.goodmorningamerica.com/living/story/gma-investig... https://www.vice.com/en/article/bj34z5/why-counterfeit-lightning-cables-kill-iphones-cheap-iphone-chargers https://www.vice.com/en/article/bj34z5/why-counterfeit-light... 'Jessa Jones, owner of iPad Rehab in Honeoye Falls' cited above is a legend https://www.youtube.com/c/Mendonipadrehab/videos https://www.youtube.com/c/Mendonipadrehab/videos
  - 6y ago

rasz 6y ago

Love Fabien write-ups! > badly fragmented connector world made of Dont forget SCSI. USB killed external SCSI. >Up to that point in time, it was a good tech stack. USB 0.9 was 1995, USB 1.0 1996. Two years later we had Bill Gates getting embarrassed by Windows 98 BSOD on stage https://www.youtube.com/watch?v=IW7Rqwwth84 https://www.youtube.com/watch?v=IW7Rqwwth84. By ~2002 we ended up with 6 separate incompatible proprietary variations on micro USB. Pretty much every second Camera vendor had its won "standard". >USB-3.X cables features 8 wires .... and the other six carry data Sadly just adding even more confusion to the mix. 24 pins, up to 13 signals, 4 pairs (8 wires) dedicated to USB 3.2 alone. >Thanks to DP 1.4, the bandwidth requirement can be lowered via DSP lossless compression oh its very much lossy, Display Stream Compression (DSC) is "visually lossless" :--------) it works similar to Texture Compression, but works on blocks of lines instead of rectangles, still it does destroy information by cutting off color accuracy. At the end of the day USB is still trivial compared to Bluetooh.

emddudley 6y ago

> Accordingly "USB 3.1 Gen 2" became "USB 3.2 Gen 1x1" and "USB 3.1 Gen 1" was renamed "USB 3.2 Gen 2x1". Is this correct? It seems swapped.

mauvehaus 6y ago

And that's just the stuff that makes a good-faith effort to the specs. My wife bought me an LED light panel for Christmas so I wouldn't be so grouchy in the winter (gift for me or her: you decide). It uses a USB mini connector for a 19.whatever volt power supply. Don't plug that into your external HDD by mistake. Yes, I know USB mini is obsolete, but we still own a couple devices that use it. And the plug is stamped with the USB logo.

citrusybread 6y ago
I have that exact same light panel. I have no idea how the manufacturer got away with it -- they're not a small company at all. I also have no idea how they ever thought that was a good idea vs just using a barrel plug.

LockAndLol 6y ago

Seriously, what is going on with USB? I bought a charging cable for my phone once that supports fast charging. The connectors all fit but no fast charging? Shipped it back and bought another one - what a waste of resources. They really need to use semantic versioning and be forced to clearly display that version number on the cable or connector in a legally defined, readable size. In fact every cable type should have that. I recently bought a 2K 144Hz screen and could get the display manager to set 144Hz. Then I looked up the standard and found out HDMI 1 doesn't support 144Hz but HDMI 2 does. Not a single cable in my house has the version number written anywhere and I had to try them out until I got the right one. What I would really appreciate is: Cable X not compatible with Cable Y --> different major versions and completely improved specs, power requirements, AND different shape Cable X.X is compatible with Cable X.Y but has different functionalities --> same major version, different minor version, same shape. Easily understandable by users "First thing I see is a big X, it fits with whatever I'm trying to connect with, it should work". If it doesn't then they can look closer and go "ooh.. the small Y is different. I should get Y or Y+n". That's it.

qwerty456127 6y ago

It was perfectly reasonable to allow partial implementations among peripherals and host controllers to let cheap and simple devices exist. But allowing different cables was a mistake. Every single USB-C cable manufactured today must be required to support Thunderbolt, high-current charging and everything.

Koshkin 6y ago

La USB ?... mais c'est très simple ! http://www.usbmadesimple.co.uk/ http://www.usbmadesimple.co.uk/