Device working on USB 2 but not on USB 3, best way to isolate the problem

[Erich Dollansky]

Hi,

I have here a several  storage devices which all work in different FreeBSD machines on USB 2. Some of them also work on an USB 3 port but most fail.

Even one USB 3 device works on USB 2 but not on USB 3.

As at least two USB 2 devices work both on USB 2 and USB 3, I expect the USB 3 port of the computer to work properly.

I did some trial and error testing but could not get a clear picture.

What would be a good strategy to find out the difference which causes the failure?

Erich