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Comment by avian

11 hours 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.

11 comments

avian

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Vogtinator  9 hours ago

AFAIK that's just when plugging in a USB 3 device into a USB 2 port or using a USB 2 cable.

  • mrandish  2 hours 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.

    • mleo  18 minutes ago

      My wife's work laptop gives this stupid warning anytime any USBC charger is plugged in, other than the Dell brick. So even a dock delivering 100w would get a complaint. The Dell brick offers non-standard charging at 140w, which can't get replaced by standards compliant, smaller chargers.

    • sokoloff  1 hour 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.

      1 reply →

imglorp  7 hours 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?

  • mrandish  2 hours 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.

  • Gigachad  7 hours 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.