USB 3 devices not reliably connecting at 5Gbps

[Erich Dollansky]

Hi,

On Fri, 11 Apr 2014 14:03:19 +0930
"Daniel O'Connor" <doconnor at gsoft.com.au> wrote:

> I have a FreeBSD 9.2 system on which I am developing a USB3 data
> acquisition card (based on the Cypress FX3) and I have found that it
> doesn't reliably connect at 5GBps - quite often it seems to only
> connect at 480MBps.
> 
> If I connect it to my macbook pro (running OSX) it reliably connects
> at 5Gbps.

allow me to share my own experience with USB3. My X220 has a single
USB3 port. I have two USB cases in which are 500GB built-in. The cases
are identical except of the serial number. But the cases came with two
different cables. FreeBSD only connects randomly at full speed when I
use the cable which came first on both cases. But it connects always
with full speed using the new cable.

It is either the error handling of FreeBSD or the quality of the
electrical signal. 

Keep this as a hint in mind when debugging your problem.

Erich