[avian]

> 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.

[Vogtinator]

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

[mrandish]

> 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]

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]

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.

[Eisenstein]

It's a chip inside the charger brick.

* https://imgur.com/gallery/spoof-original-dell-laptop-power-s...

[koyote]

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 :)

[mleo]

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.

[LoganDark]

Even Apple now has one of those, when you plug something into the USB 2 port on the MacBook Neo.

[Gigachad]

There’s still nothing when you plug a usb3 device in using a usb2 cable.

[imglorp]

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]

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]

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.

[colechristensen]

I strongly suspected my old xps had nonstandard things going on with its USB C charger