6 ms·

All these USB version names. I used to know what they all meant, but then the USB IF went ahead and renamed them all and made a bunch of versions have the same

by mort96 6mo ago

All these USB version names. I used to know what they all meant, but then the USB IF went ahead and renamed them all and made a bunch of versions have the same name and renamed some versions to have the same name as the old name of other versions. I have absolutely no idea what anyone means when they say USB 3.2 gen 2x2. I used to know what USB 3.2 meant but it's certainly not that.

ssl-3 6mo ago
Oh, it's fine. The lack of clarity is in keeping with the USB C connector itself, which may supply or accept power at various rates or not at all, may be fast or slow, may provide or accept video or not, and may even provide an interpretation of PCI Express but probably doesn't. It probably looks the same no matter what, and the cable selected to use probably also won't be very forthcoming with its capabilities either. (Be sure to drink your Ovaltine.)
- theandrewbailey 6mo ago
  This quagmire (along with the version names) is why I call it the Unintuitive Serial Bus.
- wongarsu 6mo ago
  The USB A connector stayed the same between USB 1, 2 and 3. Yet most manufacturers voluntary distinguished them by giving USB 1 and 1.1 a white insert in plug and port, USB 2 a black insert and USB 3 a blue one This was neither standarized nor enforced, yet it worked remarkably well in the real world Then we decided to just have no markings at all on USB C cables. On the ports at least we occasionally get little thunderbolt or power symbols
  - mbreese 6mo ago
    The exterior of the USB A connector stayed the same. The number of pins increased when we went from USB 2 to 3. So, even in this case, it’s slightly more complicated. The colors helped because the capabilities were very different between the ports. But when the USB IF increased the number of options (and reduced the size of the connector), different colors became impossible to do. The problem is that there are too many uses for one connector. But this is wha we wanted - a reduced number of standardized connector/power options.
    - pseudalopex 6mo ago
      > But when the USB IF increased the number of options (and reduced the size of the connector), different colors became impossible to do. Some USB C cables identify their capabilities visually or electronically. All USB C cables could do this. > But this is wha we wanted - a reduced number of standardized connector/power options. We meant who?
  - kllrnohj 6mo ago
    > Then we decided to just have no markings at all on USB C cables. I'm shocked the LTT TrueSpec cables are the first I'm aware of to so such a small and basic thing. I have so many USB C cables and no idea which are power only, USB 2 only, or what. Such a mess
- reaperducer 6mo ago
  The lack of clarity is in keeping with the USB C connector itself, which may supply or accept power at various rates or not at all, may be fast or slow, may provide or accept video or not, and may even provide an interpretation of PCI Express but probably doesn't. It gets even worse. I now have two cheap Chinese gadgets (a checki printer and a tire inflater) that have USB-C ports for charging, but will only charge with the wire that came with the gadget. The other end of which is an old-style USB plug. It seems that USB-C sockets are cheap enough parts to use them for everything, even if the manufacturer isn't going to put any actual USB circuitry behind them. Edit: Three. I forgot about my wife's illuminated makeup mirror.
  - anamexis 6mo ago
    I keep a few of these around to deal with this: https://www.adafruit.com/product/6323 https://www.adafruit.com/product/6323 Very annoying though! The devices are just missing a couple resistors which is probably less than a cent on the BOM.
    - mh- 6mo ago
      Wow, thanks for sharing this. Like the parent commenter, I have an increasing number of cheap devices like this. I wonder if anyone sells an "enclosed" version of this product. This won't survive 5 minutes in my house, haha. A quick google I found one but they're $17 each (!) and it's from a site I've never heard of and can't vouch for, so not bothering to link it here. I'm really surprised there aren't a number of these all over Amazon. Or if there are, they're using different keywords to describe them, so I can't find them.
      - anamexis 6mo ago
        Adafruit sells enclosures for them, too.
      - ssl-3 6mo ago
        On AliExpress I found some that were already packaged into neat little professional-looking adapter-sized widgets for about $2.50 each. I'd link them here, but I have a US perspective on things and it wasn't clear to me how this listing would be delivered. And delivery method is important to me, here. If with AliExpress Choice shipping, then that'd be fine: They'd show up on a doorstep in Anytown, USA for a few dollars each. But if they'd be delivered using Approximately Any Other Method, then: Surprise! Your widget valued at less than $2.50 now costs you $80 to receive! I don't want to encourage anyone to be surprised like that. (I have no doubt that an enterprising person could negotiate a very good price on 1,000 of these widgets and sell them on Amazon if they were motivated to do so.)
- tomchuk 6mo ago
  … and a M1 MacBook will source 5V/3A all day long to a non-PD negotiated sink. Somewhere between the M1 and M3 Apple decided to buy into USB-IF compliance and limit to 500mA. Has lead to some very embarrassing “works on my computer” situations on prototype boards shared with my EE colleagues (I’m a software guy who dabbles in hardware when I need to)
  - eigen 6mo ago
    I think the Rd pulldown options are for 0.9/1.5/3A without PD negotiation.
  - ssl-3 6mo ago
    It doesn't take PD negotiation to get 5v, 3A from a compliant source. A 5.1k resistor or two (quantity depends on placement in the overall circuit) is sufficient. This may be a matter of semantics, but I can't bring myself to call a resistor a negotiator. They only do one thing and they're very resistant to other options. :) With nothing connected to the CC line(s) at all, then there should be no output voltage on Vcc. It shouldn't be 5v @ 3a, or 500mA, or anything else -- it should be ~exactly 0v, and therefore also 0a. A resistor or two tells the power source what we want. Without it (or some, you know, actual PD negotiations), we get nothing. --- A careful reader will note the repeated quantity distinction. Let me explain that. Every USB C socket has both CC1 and CC2 pins. They're on opposite side of the connector and get used for sorting out PD, and for detecting the cable's connector orientation (if/when that matters). But a cromulent USB C to USB C cable can have just 1 CC wire, and that's OK. It works; it isn't even wrong. To get such a cable to coax 5v from a 5v/3a source and get power for a prototype widget on Gilligan's Island, with the cable already cut in half to get at the wires inside: Wire up power and ground to your prototype. And put a 5.1k resistor between that single CC wire and ground. Voila: We've requested 5v at up to 3a. Or: If we're being a bit more proper and snooty and want to do it The Right Way, and we actually have a USB C jack to prototype with, then that more-ideally takes two 5.1k resistors; one to pull CC1 to ground, and another to pull CC2 to ground. This does the same thing, but it does it on the connector side of things instead of the daunting no-mans-land of wires. Only one of these resistors will ever be used at one time. Or: If we have a USB C jack and can only scrounge up one 5.1k resistor (maybe we only have a single #2 pencil to whittle down to 5.1k of resistance), or we're being particularly lazy, then that's OK too. Pick CC1 or CC2 and put 5.1k between there and ground. It will work with the cable plugged in one way, and it won't work with the cable flipped 180 degrees. That can be enough to get a thing done for the moment or whatever. (There's no solution that is as permanent as a temporary one.) --- These are some of the things I learned when I was in the field and needed a 5v, >2.5a power supply to replace one that had died. I said to myself, "Self, just go over to Wal-Mart and get a 3a USB C power brick that comes with a cable, cut and splice that cable to fit the widget that needs power, and call it done. If it dies in the future, replacing it will be intuitive and fast." So dumb ol' me went to Wal-Mart and bought exactly that, and I quite confidently set forth with the splicing. This did not work. At all. And that was a harsh rabbit hole to dive into, but it was ultimately fine. After I got back that evening I soldered a 5.1k resistor (of 1206 SMD form) mid-span between the CC wire and ground, and finished the adapter-cable quite neatly with some adhesive-lined shrink tubing. Doing it this way got the customer's gear working faster than ordering the "right" parts and waiting for them show up would have, and it still works. That's all been a few years ago now; I consider it to be as permanent as anything ever really is.
izacus 6mo ago
[flagged]
- mort96 6mo ago
  Well it means I have no idea what TFA is talking about when it mentions USB versions, for one.
  - izacus 6mo ago
    [flagged]
    - mort96 6mo ago
      Why do you ask?
      - izacus 6mo ago
        Because this is an article about network adapters where someone again rants over USB markings which won't make a difference on the tested adapters if you exchange them. It's just ranting for ranting sake, not even related to topic at hand.
    - wallst07 6mo ago
      For me, it makes a difference much later on after buying some computer. I see a usb/c port and think I can plug anything into it that fits and it just works. When it doesn't, it will take hours/days to figure out why and if it comes down to a cable incompatibility, I would have already made the mistake of not knowing what I was buying.
- xattt 6mo ago
  A sense of perfect knowledge of the things around you, and not feeling like someone is trying to take advantage of you any time you go shopping.
- zoward 6mo ago
  It means that if I pick up a random USB cable and plug it into a USB port I have no idea how well it will work or even if it will work at all. It's like the U in USB stands for Unpredictable.
Latty 6mo ago
To be fair they seem to have taken this often-stated criticism on board. USB 4's naming is more sensible, and they've pushed the simple data speed & power labelling that makes it easier to work out what you need.
- mort96 6mo ago
  I don't think they've taken the criticism on board, USB 3 still has the completely nonsensical names
  - Gigachad 6mo ago
    The modern usb naming is to just list the speed or power output of the port. Rather than some absurd version number it’s now just “USB 20 Gbits”
    - mort96 6mo ago
      Then why do I still see USB 3.2 generation 2x2
      - Gigachad 6mo ago
        I'm not sure I've ever seen that on a product description. But at any rate, USB IF doesn't have any ability to enforce branding guidelines unless the product uses the official USB logo.
- usagisushi 6mo ago
  Yeah, now it's USB4 Version 2.0 / USB 80Gbps / USB4 Gen4.
  - ac29 6mo ago
    According to wikipedia the current marketing names for USB are just their speed: USB 5/10/20/40/80 Gbps. No version numbers or anything else.
PaulKeeble 6mo ago
USB is just a complete mess. I don't mind so much ports having different capabilities if they are well documented in the specification sheets of the hardware because then at least I can find out what they are capable of, but alas it never seems to be the case. Its very hard to work out whether a port can do Displayport and to what extent/performance or its true power capability or just its real data transfer speed. More often than I like I have just hoped that something works. Anything above 5W charging and 5gbps transfer is optional.
- reaperducer 6mo ago
  USB is just a complete mess. You have to go out of your way to make Apple's Lightning connector look sensible, but somehow the USB consortium has managed to do it.
  - drcongo 6mo ago
    I miss lightning. Cleanable with a toothpick and some compressed air. The USB-C port on my current iPhone is now compacted with pocket lint and I can't seem to clean it out.
    - dcrazy 6mo ago
      Toothpick and compressed air works for my phone.
    - wolvoleo 6mo ago
      It had a pretty bad flaw: the spring contacts being on the device side, causing wear and tear there. USB-C moved those to the much cheaper to replace cable. The little strip in the middle makes cleaning a bit harder but does provide for more longevity. It's s necessary evil in order to have the spring contacts on the plug side as well as not having them exposed to touch. I think the plug side of USB is pretty well designed. The problem is more with the electrical and signalling side and the marketing of the different versions.
  - ben-schaaf 6mo ago
TomatoCo 6mo ago
Going by Fabien Sanglard's cheat sheet (who I trust uncritically) https://fabiensanglard.net/usbcheat/index.html https://fabiensanglard.net/usbcheat/index.html it looks like 3.2 actually is a broader term than expected. Maybe there was some awful attempt at backwards compatibility? Or forwards?
- Someone1234 6mo ago
  Great site, thanks for the link. But holy heck, that "Also Known As" column is complete chaos. What the heck is wrong with the USB Consortium, do they have brain damage? Also, according to that table, "USB4 Gen 2×2" is a downgrade on "USB 3.2 Gen 2x2", since the cable length is 0.8m instead of 1m for the same speeds. Which is uhh unexpected.
  - BearOso 6mo ago
    The cable length is only for the spec. You can get longer cables that achieve the higher bandwidth, they're just not certified for that.
    - mort96 6mo ago
      And? The question stands, why is the USB 4 spec a downgrade?
      - BearOso 6mo ago
        Probably because with USB 3.2 2x2 they were reviewing too many longer cables that didn't meet the requirements, so they lowered the length so companies didn't submit them only to fail to get certified. It's worth noting that 1.2m is now in the USB4 spec.
    - Someone1234 6mo ago
      Right, so per spec it is a downgrade.
  - wpm 6mo ago
renticulous 6mo ago
I predict in future when our civilization will advance to higher level, this phenomenon will happen with english words and jargons. e.g. here are versioned and namespaced words. topology.bio.23, topology.math.45 etc. Welcome to the brave new world we will enter in far future.
adrian_b 6mo ago
Unfortunately "USB 3.2" is just a version of the standard, which does not give any information about the performance of a USB port or device. USB 5 Gb/s = USB 3.2 gen 1, available on Type A or Type C connectors (or on devices on a special extended micro B connector) USB 10 Gb/s = USB 3.2 gen 2, available on Type A or Type C connectors USB 20 Gb/s = USB 3.2 gen 2x2, available only on Type C connectors Moreover, "5 Gb/s" is a marketing lie. The so-called USB of 5 Gb/s has a speed of 4 Gb/s (the same as PCIe 2.0). On the other hand, 10 Gb/s and 20 Gb/s, have the claimed speeds, so USB of 10 Gb/s is 2.5 times faster than USB of 5 Gb/s, not 2 times faster. 10 Gb/s USB and Ethernet have truly the same speed, but the USB overhead is somewhat higher, leading to a somewhat lower speed. However, the speed shown in TFA, not much higher than 7 Gb/s seems too low, and it may be caused by the Windows drivers. It is possible that on other operating systems, e.g. Linux, one can get a higher transfer speed.
- mbreese 6mo ago
  The fact that you had to list all of the versions and speeds at the top of your post is illustrative of what the parent was trying to say. We can all look up what speed is associated with what version, but it’s not exactly a consumer friendly experience.
  - adrian_b 6mo ago
    A few computer manufacturers do the right thing and they mark the speed on the USB ports, removing ambiguities, for example ASUS does this on my NUCs and motherboards. Unfortunately, there are too many who do not do this, even among the biggest computer vendors.
    - riobard 6mo ago
      > mark the speed on the USB ports, removing ambiguities Unfortunately it's not true. Quiz: what happens when a device capable of 20Gbps is plugged into a port marked as 40Gbps?
      - ziml77 6mo ago
compounding_it 6mo ago
In all this, people now just go to the Apple Store and buy a cable for their Apple device. This confusion benefitted such vendors and now they sell 1$ cable for an absurd amount of profit.
post-it 6mo ago
I will say, casual users don't really care. Pretty much any combination of a wall plug and a cable will charge a phone at acceptable speeds, and that's all 99% of people need.
robotnikman 6mo ago
In my experience, its just best to stick with Thunderbolt when you want to make sure you are getting the best speed for external devices that require it (external SSD's, Graphics Cards, Network adapters) Much easier and reliable than navigating the confusing sea of USB standards
- jasomill 6mo ago
  While I generally agree, there are still corner cases: As I mentioned above, a Thunderbolt port can end up with less dedicated bandwidth than a 10 Gbps USB port due to PCIe lane configuration. Thunderbolt 3 only provides 22 Gbps PCIe bandwidth even if only a single device is connected. Apple's TB2-to-TB3 adapter will connect any TB2 device to any TB3 host, and any TB3 (not USB) device to any TB2 host unless it's bus powered, in which case you need to daisy-chain a second TB3 device with two ports to supply power. While Thunderbolt 4 and USB 4 PCIe are largely interchangeable, and while Thunderbolt 4 devices are backwards-compatible with Thunderbolt 3 hosts, USB 4 PCIe devices are not required to support Thunderbolt 3 hosts.

by mort96 6mo ago

ssl-3 6mo ago

Oh, it's fine. The lack of clarity is in keeping with the USB C connector itself, which may supply or accept power at various rates or not at all, may be fast or slow, may provide or accept video or not, and may even provide an interpretation of PCI Express but probably doesn't. It probably looks the same no matter what, and the cable selected to use probably also won't be very forthcoming with its capabilities either. (Be sure to drink your Ovaltine.)

theandrewbailey 6mo ago
This quagmire (along with the version names) is why I call it the Unintuitive Serial Bus.
wongarsu 6mo ago
The USB A connector stayed the same between USB 1, 2 and 3. Yet most manufacturers voluntary distinguished them by giving USB 1 and 1.1 a white insert in plug and port, USB 2 a black insert and USB 3 a blue one This was neither standarized nor enforced, yet it worked remarkably well in the real world Then we decided to just have no markings at all on USB C cables. On the ports at least we occasionally get little thunderbolt or power symbols
- mbreese 6mo ago
  The exterior of the USB A connector stayed the same. The number of pins increased when we went from USB 2 to 3. So, even in this case, it’s slightly more complicated. The colors helped because the capabilities were very different between the ports. But when the USB IF increased the number of options (and reduced the size of the connector), different colors became impossible to do. The problem is that there are too many uses for one connector. But this is wha we wanted - a reduced number of standardized connector/power options.
  - pseudalopex 6mo ago
    > But when the USB IF increased the number of options (and reduced the size of the connector), different colors became impossible to do. Some USB C cables identify their capabilities visually or electronically. All USB C cables could do this. > But this is wha we wanted - a reduced number of standardized connector/power options. We meant who?
- kllrnohj 6mo ago
  > Then we decided to just have no markings at all on USB C cables. I'm shocked the LTT TrueSpec cables are the first I'm aware of to so such a small and basic thing. I have so many USB C cables and no idea which are power only, USB 2 only, or what. Such a mess
reaperducer 6mo ago
The lack of clarity is in keeping with the USB C connector itself, which may supply or accept power at various rates or not at all, may be fast or slow, may provide or accept video or not, and may even provide an interpretation of PCI Express but probably doesn't. It gets even worse. I now have two cheap Chinese gadgets (a checki printer and a tire inflater) that have USB-C ports for charging, but will only charge with the wire that came with the gadget. The other end of which is an old-style USB plug. It seems that USB-C sockets are cheap enough parts to use them for everything, even if the manufacturer isn't going to put any actual USB circuitry behind them. Edit: Three. I forgot about my wife's illuminated makeup mirror.
- anamexis 6mo ago
  I keep a few of these around to deal with this: https://www.adafruit.com/product/6323 https://www.adafruit.com/product/6323 Very annoying though! The devices are just missing a couple resistors which is probably less than a cent on the BOM.
  - mh- 6mo ago
    Wow, thanks for sharing this. Like the parent commenter, I have an increasing number of cheap devices like this. I wonder if anyone sells an "enclosed" version of this product. This won't survive 5 minutes in my house, haha. A quick google I found one but they're $17 each (!) and it's from a site I've never heard of and can't vouch for, so not bothering to link it here. I'm really surprised there aren't a number of these all over Amazon. Or if there are, they're using different keywords to describe them, so I can't find them.
    - anamexis 6mo ago
      Adafruit sells enclosures for them, too.
    - ssl-3 6mo ago
      On AliExpress I found some that were already packaged into neat little professional-looking adapter-sized widgets for about $2.50 each. I'd link them here, but I have a US perspective on things and it wasn't clear to me how this listing would be delivered. And delivery method is important to me, here. If with AliExpress Choice shipping, then that'd be fine: They'd show up on a doorstep in Anytown, USA for a few dollars each. But if they'd be delivered using Approximately Any Other Method, then: Surprise! Your widget valued at less than $2.50 now costs you $80 to receive! I don't want to encourage anyone to be surprised like that. (I have no doubt that an enterprising person could negotiate a very good price on 1,000 of these widgets and sell them on Amazon if they were motivated to do so.)
tomchuk 6mo ago
… and a M1 MacBook will source 5V/3A all day long to a non-PD negotiated sink. Somewhere between the M1 and M3 Apple decided to buy into USB-IF compliance and limit to 500mA. Has lead to some very embarrassing “works on my computer” situations on prototype boards shared with my EE colleagues (I’m a software guy who dabbles in hardware when I need to)
- eigen 6mo ago
  I think the Rd pulldown options are for 0.9/1.5/3A without PD negotiation.
- ssl-3 6mo ago
  It doesn't take PD negotiation to get 5v, 3A from a compliant source. A 5.1k resistor or two (quantity depends on placement in the overall circuit) is sufficient. This may be a matter of semantics, but I can't bring myself to call a resistor a negotiator. They only do one thing and they're very resistant to other options. :) With nothing connected to the CC line(s) at all, then there should be no output voltage on Vcc. It shouldn't be 5v @ 3a, or 500mA, or anything else -- it should be ~exactly 0v, and therefore also 0a. A resistor or two tells the power source what we want. Without it (or some, you know, actual PD negotiations), we get nothing. --- A careful reader will note the repeated quantity distinction. Let me explain that. Every USB C socket has both CC1 and CC2 pins. They're on opposite side of the connector and get used for sorting out PD, and for detecting the cable's connector orientation (if/when that matters). But a cromulent USB C to USB C cable can have just 1 CC wire, and that's OK. It works; it isn't even wrong. To get such a cable to coax 5v from a 5v/3a source and get power for a prototype widget on Gilligan's Island, with the cable already cut in half to get at the wires inside: Wire up power and ground to your prototype. And put a 5.1k resistor between that single CC wire and ground. Voila: We've requested 5v at up to 3a. Or: If we're being a bit more proper and snooty and want to do it The Right Way, and we actually have a USB C jack to prototype with, then that more-ideally takes two 5.1k resistors; one to pull CC1 to ground, and another to pull CC2 to ground. This does the same thing, but it does it on the connector side of things instead of the daunting no-mans-land of wires. Only one of these resistors will ever be used at one time. Or: If we have a USB C jack and can only scrounge up one 5.1k resistor (maybe we only have a single #2 pencil to whittle down to 5.1k of resistance), or we're being particularly lazy, then that's OK too. Pick CC1 or CC2 and put 5.1k between there and ground. It will work with the cable plugged in one way, and it won't work with the cable flipped 180 degrees. That can be enough to get a thing done for the moment or whatever. (There's no solution that is as permanent as a temporary one.) --- These are some of the things I learned when I was in the field and needed a 5v, >2.5a power supply to replace one that had died. I said to myself, "Self, just go over to Wal-Mart and get a 3a USB C power brick that comes with a cable, cut and splice that cable to fit the widget that needs power, and call it done. If it dies in the future, replacing it will be intuitive and fast." So dumb ol' me went to Wal-Mart and bought exactly that, and I quite confidently set forth with the splicing. This did not work. At all. And that was a harsh rabbit hole to dive into, but it was ultimately fine. After I got back that evening I soldered a 5.1k resistor (of 1206 SMD form) mid-span between the CC wire and ground, and finished the adapter-cable quite neatly with some adhesive-lined shrink tubing. Doing it this way got the customer's gear working faster than ordering the "right" parts and waiting for them show up would have, and it still works. That's all been a few years ago now; I consider it to be as permanent as anything ever really is.

izacus 6mo ago

[flagged]

mort96 6mo ago
Well it means I have no idea what TFA is talking about when it mentions USB versions, for one.
- izacus 6mo ago
  [flagged]
  - mort96 6mo ago
    Why do you ask?
    - izacus 6mo ago
      Because this is an article about network adapters where someone again rants over USB markings which won't make a difference on the tested adapters if you exchange them. It's just ranting for ranting sake, not even related to topic at hand.
  - wallst07 6mo ago
    For me, it makes a difference much later on after buying some computer. I see a usb/c port and think I can plug anything into it that fits and it just works. When it doesn't, it will take hours/days to figure out why and if it comes down to a cable incompatibility, I would have already made the mistake of not knowing what I was buying.
xattt 6mo ago
A sense of perfect knowledge of the things around you, and not feeling like someone is trying to take advantage of you any time you go shopping.
zoward 6mo ago
It means that if I pick up a random USB cable and plug it into a USB port I have no idea how well it will work or even if it will work at all. It's like the U in USB stands for Unpredictable.

Latty 6mo ago

To be fair they seem to have taken this often-stated criticism on board. USB 4's naming is more sensible, and they've pushed the simple data speed & power labelling that makes it easier to work out what you need.

mort96 6mo ago
I don't think they've taken the criticism on board, USB 3 still has the completely nonsensical names
- Gigachad 6mo ago
  The modern usb naming is to just list the speed or power output of the port. Rather than some absurd version number it’s now just “USB 20 Gbits”
  - mort96 6mo ago
    Then why do I still see USB 3.2 generation 2x2
    - Gigachad 6mo ago
      I'm not sure I've ever seen that on a product description. But at any rate, USB IF doesn't have any ability to enforce branding guidelines unless the product uses the official USB logo.
usagisushi 6mo ago
Yeah, now it's USB4 Version 2.0 / USB 80Gbps / USB4 Gen4.
- ac29 6mo ago
  According to wikipedia the current marketing names for USB are just their speed: USB 5/10/20/40/80 Gbps. No version numbers or anything else.

PaulKeeble 6mo ago

USB is just a complete mess. I don't mind so much ports having different capabilities if they are well documented in the specification sheets of the hardware because then at least I can find out what they are capable of, but alas it never seems to be the case. Its very hard to work out whether a port can do Displayport and to what extent/performance or its true power capability or just its real data transfer speed. More often than I like I have just hoped that something works. Anything above 5W charging and 5gbps transfer is optional.

reaperducer 6mo ago
USB is just a complete mess. You have to go out of your way to make Apple's Lightning connector look sensible, but somehow the USB consortium has managed to do it.
- drcongo 6mo ago
  I miss lightning. Cleanable with a toothpick and some compressed air. The USB-C port on my current iPhone is now compacted with pocket lint and I can't seem to clean it out.
  - dcrazy 6mo ago
    Toothpick and compressed air works for my phone.
  - wolvoleo 6mo ago
    It had a pretty bad flaw: the spring contacts being on the device side, causing wear and tear there. USB-C moved those to the much cheaper to replace cable. The little strip in the middle makes cleaning a bit harder but does provide for more longevity. It's s necessary evil in order to have the spring contacts on the plug side as well as not having them exposed to touch. I think the plug side of USB is pretty well designed. The problem is more with the electrical and signalling side and the marketing of the different versions.
- ben-schaaf 6mo ago

TomatoCo 6mo ago

Going by Fabien Sanglard's cheat sheet (who I trust uncritically) https://fabiensanglard.net/usbcheat/index.html https://fabiensanglard.net/usbcheat/index.html it looks like 3.2 actually is a broader term than expected. Maybe there was some awful attempt at backwards compatibility? Or forwards?

Someone1234 6mo ago
Great site, thanks for the link. But holy heck, that "Also Known As" column is complete chaos. What the heck is wrong with the USB Consortium, do they have brain damage? Also, according to that table, "USB4 Gen 2×2" is a downgrade on "USB 3.2 Gen 2x2", since the cable length is 0.8m instead of 1m for the same speeds. Which is uhh unexpected.
- BearOso 6mo ago
  The cable length is only for the spec. You can get longer cables that achieve the higher bandwidth, they're just not certified for that.
  - mort96 6mo ago
    And? The question stands, why is the USB 4 spec a downgrade?
    - BearOso 6mo ago
      Probably because with USB 3.2 2x2 they were reviewing too many longer cables that didn't meet the requirements, so they lowered the length so companies didn't submit them only to fail to get certified. It's worth noting that 1.2m is now in the USB4 spec.
  - Someone1234 6mo ago
    Right, so per spec it is a downgrade.
- wpm 6mo ago

renticulous 6mo ago

I predict in future when our civilization will advance to higher level, this phenomenon will happen with english words and jargons. e.g. here are versioned and namespaced words. topology.bio.23, topology.math.45 etc. Welcome to the brave new world we will enter in far future.

adrian_b 6mo ago

Unfortunately "USB 3.2" is just a version of the standard, which does not give any information about the performance of a USB port or device. USB 5 Gb/s = USB 3.2 gen 1, available on Type A or Type C connectors (or on devices on a special extended micro B connector) USB 10 Gb/s = USB 3.2 gen 2, available on Type A or Type C connectors USB 20 Gb/s = USB 3.2 gen 2x2, available only on Type C connectors Moreover, "5 Gb/s" is a marketing lie. The so-called USB of 5 Gb/s has a speed of 4 Gb/s (the same as PCIe 2.0). On the other hand, 10 Gb/s and 20 Gb/s, have the claimed speeds, so USB of 10 Gb/s is 2.5 times faster than USB of 5 Gb/s, not 2 times faster. 10 Gb/s USB and Ethernet have truly the same speed, but the USB overhead is somewhat higher, leading to a somewhat lower speed. However, the speed shown in TFA, not much higher than 7 Gb/s seems too low, and it may be caused by the Windows drivers. It is possible that on other operating systems, e.g. Linux, one can get a higher transfer speed.

mbreese 6mo ago
The fact that you had to list all of the versions and speeds at the top of your post is illustrative of what the parent was trying to say. We can all look up what speed is associated with what version, but it’s not exactly a consumer friendly experience.
- adrian_b 6mo ago
  A few computer manufacturers do the right thing and they mark the speed on the USB ports, removing ambiguities, for example ASUS does this on my NUCs and motherboards. Unfortunately, there are too many who do not do this, even among the biggest computer vendors.
  - riobard 6mo ago
    > mark the speed on the USB ports, removing ambiguities Unfortunately it's not true. Quiz: what happens when a device capable of 20Gbps is plugged into a port marked as 40Gbps?
    - ziml77 6mo ago

compounding_it 6mo ago

In all this, people now just go to the Apple Store and buy a cable for their Apple device. This confusion benefitted such vendors and now they sell 1$ cable for an absurd amount of profit.

post-it 6mo ago

I will say, casual users don't really care. Pretty much any combination of a wall plug and a cable will charge a phone at acceptable speeds, and that's all 99% of people need.

robotnikman 6mo ago

In my experience, its just best to stick with Thunderbolt when you want to make sure you are getting the best speed for external devices that require it (external SSD's, Graphics Cards, Network adapters) Much easier and reliable than navigating the confusing sea of USB standards

jasomill 6mo ago
While I generally agree, there are still corner cases: As I mentioned above, a Thunderbolt port can end up with less dedicated bandwidth than a 10 Gbps USB port due to PCIe lane configuration. Thunderbolt 3 only provides 22 Gbps PCIe bandwidth even if only a single device is connected. Apple's TB2-to-TB3 adapter will connect any TB2 device to any TB3 host, and any TB3 (not USB) device to any TB2 host unless it's bus powered, in which case you need to daisy-chain a second TB3 device with two ports to supply power. While Thunderbolt 4 and USB 4 PCIe are largely interchangeable, and while Thunderbolt 4 devices are backwards-compatible with Thunderbolt 3 hosts, USB 4 PCIe devices are not required to support Thunderbolt 3 hosts.