[_adamb]

Yeah, I would like a test device that could let me know which transfer rates a cable supports. I've got a huge pile of USBC cables (and adapters). A good chunk of them might even be USB 2.0!

It seems like a device capable of acting as a host & device could just try to shove data down a cable and see what the max is...

[newaccount74]

On the Mac, there's a simple way to check cables:

Take a USB3 device, plug it in with the cable, and then go to System Profiler (Apple Menu -> About this Mac -> System Profiler). Look for the device, and check the speed. If it says 480MB/s it's a USB 2 cable, if it says 5GB/s, 10GB/s or 20GB/s then it's a USB3 cable.

I assume there's a way to do the same thing on Windows and Linux.

[hanche]

I just tested that, and it works. Using a Samsung T7 SSD. Clever. Now I wonder if a similar trick works for power capabilities?