5 ms·

The thing that has been bothering me for a while is that the USB spec allows for software detection of capabilities. You can read the emarker data and see the s

The thing that has been bothering me for a while is that the USB spec allows for software detection of capabilities. You can read the emarker data and see the supported protocols, speeds, voltages, etc. But there is not standard for usb controllers to present this data to the OS. So it’s stuck in the low level firmware and never passed up. In theory we could have a popup box that tells you that both your computer and other device support higher speeds/more power, but your cable is limiting it. Apple seems best able to do this since they control the hardware and OS, yet they aren’t doing it either. Users are just left to be confused about why things are slow.

avian 7mo ago
> In theory we could have a popup box that tells you that both your computer and other device support higher speeds/more power, but your cable is limiting it. I'm pretty sure my old Dell XPS laptop with Windows 10 had pop-ups just like this. "This device can run faster" or something.
- LoganDark 7mo ago
  Even Apple now has one of those, when you plug something into the USB 2 port on the MacBook Neo.
  - Gigachad 7mo ago
    There’s still nothing when you plug a usb3 device in using a usb2 cable.
- Vogtinator 7mo ago
  AFAIK that's just when plugging in a USB 3 device into a USB 2 port or using a USB 2 cable.
  - mrandish 7mo ago
    > that's just when plugging in a USB 3 device into a USB 2 port Dell XPS laptops (and some others) can also warn if the charger isn't providing the full wattage the laptop is rated for. This warning is an option that can be turned off in the BIOS settings. I usually turn it off because I sometimes intentionally do day trips with a smaller/lighter portable charger which delivers 45w to my laptop which can need up to 65w due to having a discrete GPU. However, 45w is more than sufficient to charge the laptop during normal use on the Balanced power plan with iGPU. I only need more than 45w when gaming with the discrete GPU active.
    - sokoloff 7mo ago
      Just this morning, my old Latitude failed to boot with a “this charger is only giving 20W and that’s not enough to boot this laptop” error. (I was testing a new USB-C charger that’s obviously going back.) Weirdest part was it was 100% charged, so could have booted with 0 Watts of charger but decided not to boot with 20 Watts more.
      - mrandish 7mo ago
        Oh, refusing to boot at all is evil. I've never seen that. Sure, you or I would just unplug the charger and run on battery but bad UX decisions like that generate a support call to me from my 95 yr old mom. It should not only warn and continue to boot, it should use whatever power is on offer to reduce the rate of battery drain.
      - koyote 7mo ago
        Interesting that it refused to boot. If I have a lower wattage charger connected on booth it shows me that information but I can just press enter to continue. It's just a warning. Maybe it's a bios setting? Workaround is of course to boot without a charger connected and then connect it later :)
      - Eisenstein 7mo ago
        It's a chip inside the charger brick. * https://imgur.com/gallery/spoof-original-dell-laptop-power-supply-by-splicing-authentication-chip-absz7QI https://imgur.com/gallery/spoof-original-dell-laptop-power-s...
- imglorp 7mo ago
  I wonder if it's possible for a regular machine with two high speed ports to do a cable test by itself. Maybe it can't test all the attributes but could it at least verify speed claims in software?
  - Gigachad 7mo ago
    There would be too many factors involved for a proper test. Many laptop USB controllers would probably not even have the capacity to run two ports at full speed simultaneously.
  - mrandish 7mo ago
    Apparently the USB driver stack doesn't report the cable's eMarker chip data back to the OS. However benchmarking actual transfer throughput is the ultimate test for data connections (vs charging use cases). Unfortunately, TFA doesn't really go into this aspect of cable testing as the tester seems to only report eMarker data, which pins are connected and copper resistance. Since a >$1,000 automated lab cable throughput tester is overkill, my thumbnail test for high-speed USB-C data cables is to run a disk speed benchmark to a very fast, well-characterized external NVMe enclosure with a known-fast NVMe drive. I know what the throughput should be based on prior tests with an $80 active 1M Thunderbolt cable made for high-end USB-C docks and confirmed by online benchmark reviews from credible sources.
- colechristensen 7mo ago
  I strongly suspected my old xps had nonstandard things going on with its USB C charger
graemep 7mo ago
I suspect most users do not even realise things are slow.
- TeMPOraL 7mo ago
  Oh, they very much do. But like with everything in technology, they can do fuck all about it, so they resign and maybe complain to you occasionally if you're the designated (in)voluntary tech support person for your family and friends. Regular people hate technology, both for how magical and how badly broken it is, but they've long learned they're powerless to change it - nobody listens to their complaints, and the whole market is supply-driven, i.e. you get to choose from what vendors graciously put on the market, not from what the space of possible devices.
  - ChrisMarshallNY 7mo ago
    They also tend to hate technology, because us nerds are often unbearable. They hate having to go through people that get them upset, in order to use their kit. Not just tech (although it’s more prevalent). People who are “handy” can also be that way (but, for some reason, techies tend to be more abrasive). I’ve learned the utility of being patient, and not showing the exasperation that is often boiling inside of me.
    - tomcam 7mo ago
      Amen. I couldn’t have said it better. In general for the 40+ years I’ve been a programmer I have detested the practice of not surfacing diagnostic information to users when technology makes it possible to do so in a clear and unambiguous way.
      - graemep 7mo ago
        Most users tend to ignore diagnostic information. "What did the error message say" "I don't know."
        7mo ago
QuantumNomad_ 7mo ago
On iPhone, when connecting an external MIDI device via USB, the phone told me that the device was drawing too much power and would be disabled. I don’t know if they check that via USB protocol, or if they are measuring the actual power draw on the USB port. In order to use the device, I had to connect it via an externally powered USB hub.
vladvasiliu 7mo ago
> But there is not standard for usb controllers to present this data to the OS. So it’s stuck in the low level firmware and never passed up. In theory we could have a popup box that tells you that both your computer and other device support higher speeds/more power, but your cable is limiting it. There is. I used to use a KVM with USB 2 ports connected to my PC's USB 3 port, to which I connected a monitor with integrated USB 3 hub to drive my keyboard and mouse. Windows would show a popup every time telling me that I should use a faster cable. There are also popups telling me that my laptop is connected to a "slow" usb-c charger.
- Forgeties79 7mo ago
  I have seen these kinds of notifications on occasion but they are far from the norm.
- wholinator2 7mo ago
  I've used all manner of archaic usb cables for data transfer when in a pinch and windows has never shown me anything at all. Could it be the external device you were connecting to triggering the windows notification?
- bdavbdav 7mo ago
  That’s quite a simplistic one unfortunately - USB 2 and 3 use different controllers in the PC, which it can indeed detect. The sub-flavours of 3/4 less so.
Barbing 7mo ago
Perhaps someday it will earn the same level of importance as charging; iOS 26 calls out slow chargers on their iPhones, so you can run to the Apple Store and buy a fast one! They probably have to weigh potential new hardware sales against added complexity. I have counterpoints too but: I believe they try to protect users’ mental models of their ecosystem (which perhaps I appreciate when I don’t notice, and can’t stand when something is uncustomizable). Like there are enough variables they don’t trust us with as it is.
- tredre3 7mo ago
  > iOS 26 calls out slow chargers on their iPhones, so you can run to the Apple Store and buy a fast one! You jest but that notification (it's been a thing on Android for at least 8 years, and on thinkpads for at least 10) has been very helpful to me. Sometimes the negotiation just fails and being told is helpful. Sometimes the charger lies about its specs and once again it's helpful to have a hint, rather than expect everybody to systematically have usb testers on hand.
  - s3p 7mo ago
    This one is pretty simple to do. It requests a voltage and then starts pulling current and monitors the voltage as it increases its current draw. If the voltage goes down, alert the user. With data speed I think it could be a little more complicated. Like OP was saying it would need access to some level of hardware information where it can see which pins are used by the cable. Since the connection 'speed' is still variable even when you DO have a supported cable.
  - Barbing 7mo ago
    I do jest, it’s a great feature. I never considered charger negotiation failure!
pseudohadamard 7mo ago
Does it matter, for anyone other than hardcore geeks? All the OS would care about is how much power can it deliver and what data speed it provides, not whether the exception handling on page 4,096, section 4(a)2.1, paragraph 4 of the spec, has been implemented.
prism56 7mo ago
Android must have this in some form. My Pixel phone with a third-party app can show the voltage and current mode selected via the PD protocols. Using DevCheck might show 2.2A/9V as an example.
EnnEmmEss 7mo ago
It's fun to see the Treedix tester come up on HN. I got one a few months back and have quite enjoyed using it. One thing which I did find interesting was that one of the cables had the emarker data lie. IIRC, the emarker data would suggested it supported much higher speeds and wattage than it did. Fortunately, the other testing screens successfully detected it only had USB 2.0 wires even though it claimed to support 40 GB/s.

avian 7mo ago

> In theory we could have a popup box that tells you that both your computer and other device support higher speeds/more power, but your cable is limiting it. I'm pretty sure my old Dell XPS laptop with Windows 10 had pop-ups just like this. "This device can run faster" or something.

LoganDark 7mo ago
Even Apple now has one of those, when you plug something into the USB 2 port on the MacBook Neo.
- Gigachad 7mo ago
  There’s still nothing when you plug a usb3 device in using a usb2 cable.
Vogtinator 7mo ago
AFAIK that's just when plugging in a USB 3 device into a USB 2 port or using a USB 2 cable.
- mrandish 7mo ago
  > that's just when plugging in a USB 3 device into a USB 2 port Dell XPS laptops (and some others) can also warn if the charger isn't providing the full wattage the laptop is rated for. This warning is an option that can be turned off in the BIOS settings. I usually turn it off because I sometimes intentionally do day trips with a smaller/lighter portable charger which delivers 45w to my laptop which can need up to 65w due to having a discrete GPU. However, 45w is more than sufficient to charge the laptop during normal use on the Balanced power plan with iGPU. I only need more than 45w when gaming with the discrete GPU active.
  - sokoloff 7mo ago
    Just this morning, my old Latitude failed to boot with a “this charger is only giving 20W and that’s not enough to boot this laptop” error. (I was testing a new USB-C charger that’s obviously going back.) Weirdest part was it was 100% charged, so could have booted with 0 Watts of charger but decided not to boot with 20 Watts more.
    - mrandish 7mo ago
      Oh, refusing to boot at all is evil. I've never seen that. Sure, you or I would just unplug the charger and run on battery but bad UX decisions like that generate a support call to me from my 95 yr old mom. It should not only warn and continue to boot, it should use whatever power is on offer to reduce the rate of battery drain.
    - koyote 7mo ago
      Interesting that it refused to boot. If I have a lower wattage charger connected on booth it shows me that information but I can just press enter to continue. It's just a warning. Maybe it's a bios setting? Workaround is of course to boot without a charger connected and then connect it later :)
    - Eisenstein 7mo ago
      It's a chip inside the charger brick. * https://imgur.com/gallery/spoof-original-dell-laptop-power-supply-by-splicing-authentication-chip-absz7QI https://imgur.com/gallery/spoof-original-dell-laptop-power-s...
imglorp 7mo ago
I wonder if it's possible for a regular machine with two high speed ports to do a cable test by itself. Maybe it can't test all the attributes but could it at least verify speed claims in software?
- Gigachad 7mo ago
  There would be too many factors involved for a proper test. Many laptop USB controllers would probably not even have the capacity to run two ports at full speed simultaneously.
- mrandish 7mo ago
  Apparently the USB driver stack doesn't report the cable's eMarker chip data back to the OS. However benchmarking actual transfer throughput is the ultimate test for data connections (vs charging use cases). Unfortunately, TFA doesn't really go into this aspect of cable testing as the tester seems to only report eMarker data, which pins are connected and copper resistance. Since a >$1,000 automated lab cable throughput tester is overkill, my thumbnail test for high-speed USB-C data cables is to run a disk speed benchmark to a very fast, well-characterized external NVMe enclosure with a known-fast NVMe drive. I know what the throughput should be based on prior tests with an $80 active 1M Thunderbolt cable made for high-end USB-C docks and confirmed by online benchmark reviews from credible sources.
colechristensen 7mo ago
I strongly suspected my old xps had nonstandard things going on with its USB C charger

graemep 7mo ago

I suspect most users do not even realise things are slow.

TeMPOraL 7mo ago
Oh, they very much do. But like with everything in technology, they can do fuck all about it, so they resign and maybe complain to you occasionally if you're the designated (in)voluntary tech support person for your family and friends. Regular people hate technology, both for how magical and how badly broken it is, but they've long learned they're powerless to change it - nobody listens to their complaints, and the whole market is supply-driven, i.e. you get to choose from what vendors graciously put on the market, not from what the space of possible devices.
- ChrisMarshallNY 7mo ago
  They also tend to hate technology, because us nerds are often unbearable. They hate having to go through people that get them upset, in order to use their kit. Not just tech (although it’s more prevalent). People who are “handy” can also be that way (but, for some reason, techies tend to be more abrasive). I’ve learned the utility of being patient, and not showing the exasperation that is often boiling inside of me.
  - tomcam 7mo ago
    Amen. I couldn’t have said it better. In general for the 40+ years I’ve been a programmer I have detested the practice of not surfacing diagnostic information to users when technology makes it possible to do so in a clear and unambiguous way.
    - graemep 7mo ago
      Most users tend to ignore diagnostic information. "What did the error message say" "I don't know."
      - 7mo ago

QuantumNomad_ 7mo ago

On iPhone, when connecting an external MIDI device via USB, the phone told me that the device was drawing too much power and would be disabled. I don’t know if they check that via USB protocol, or if they are measuring the actual power draw on the USB port. In order to use the device, I had to connect it via an externally powered USB hub.

vladvasiliu 7mo ago

> But there is not standard for usb controllers to present this data to the OS. So it’s stuck in the low level firmware and never passed up. In theory we could have a popup box that tells you that both your computer and other device support higher speeds/more power, but your cable is limiting it. There is. I used to use a KVM with USB 2 ports connected to my PC's USB 3 port, to which I connected a monitor with integrated USB 3 hub to drive my keyboard and mouse. Windows would show a popup every time telling me that I should use a faster cable. There are also popups telling me that my laptop is connected to a "slow" usb-c charger.

Forgeties79 7mo ago
I have seen these kinds of notifications on occasion but they are far from the norm.
wholinator2 7mo ago
I've used all manner of archaic usb cables for data transfer when in a pinch and windows has never shown me anything at all. Could it be the external device you were connecting to triggering the windows notification?
bdavbdav 7mo ago
That’s quite a simplistic one unfortunately - USB 2 and 3 use different controllers in the PC, which it can indeed detect. The sub-flavours of 3/4 less so.

Barbing 7mo ago

Perhaps someday it will earn the same level of importance as charging; iOS 26 calls out slow chargers on their iPhones, so you can run to the Apple Store and buy a fast one! They probably have to weigh potential new hardware sales against added complexity. I have counterpoints too but: I believe they try to protect users’ mental models of their ecosystem (which perhaps I appreciate when I don’t notice, and can’t stand when something is uncustomizable). Like there are enough variables they don’t trust us with as it is.

tredre3 7mo ago
> iOS 26 calls out slow chargers on their iPhones, so you can run to the Apple Store and buy a fast one! You jest but that notification (it's been a thing on Android for at least 8 years, and on thinkpads for at least 10) has been very helpful to me. Sometimes the negotiation just fails and being told is helpful. Sometimes the charger lies about its specs and once again it's helpful to have a hint, rather than expect everybody to systematically have usb testers on hand.
- s3p 7mo ago
  This one is pretty simple to do. It requests a voltage and then starts pulling current and monitors the voltage as it increases its current draw. If the voltage goes down, alert the user. With data speed I think it could be a little more complicated. Like OP was saying it would need access to some level of hardware information where it can see which pins are used by the cable. Since the connection 'speed' is still variable even when you DO have a supported cable.
- Barbing 7mo ago
  I do jest, it’s a great feature. I never considered charger negotiation failure!

pseudohadamard 7mo ago

Does it matter, for anyone other than hardcore geeks? All the OS would care about is how much power can it deliver and what data speed it provides, not whether the exception handling on page 4,096, section 4(a)2.1, paragraph 4 of the spec, has been implemented.

prism56 7mo ago

Android must have this in some form. My Pixel phone with a third-party app can show the voltage and current mode selected via the PD protocols. Using DevCheck might show 2.2A/9V as an example.

EnnEmmEss 7mo ago

It's fun to see the Treedix tester come up on HN. I got one a few months back and have quite enjoyed using it. One thing which I did find interesting was that one of the cables had the emarker data lie. IIRC, the emarker data would suggested it supported much higher speeds and wattage than it did. Fortunately, the other testing screens successfully detected it only had USB 2.0 wires even though it claimed to support 40 GB/s.