Just discovered the reason my USB 3.0 stopped working, is the 10.11.6 update! I had it installed in PCI slot 2, to get the max out of 2x SM951...so initially I thought the usb 3.0 didn't work, had something to do with the 16 lane. I have another 6 core, so I tried the usb 3.0 in that one (still 10.11.5), and no problem. So installed the usb 3.0 in pci slot 4, on the 10.11.6 MP...and no go!
Which card? 10.11.6 didn't kill USB 3.0, at most, it kill some card with specific controller. So, I think it's better to know which card. So that we can confirm what's happening. Or know who should not upgrade (if he get the same card).
True that, but this card prooved very reliable, I had to switch cards before! And I have it in many other Macs, and tipped many for this one. I'm sure its no coincedance http://www.ebay.com/itm/4-Port-Supe...029569?hash=item3d09007381:g:WcsAAOSwepZXTcxN
That's strange, from the screen capture in your link. It looks like this card use the FL1100 controller, same as my KT-4004. My card works fine with all the 10.11.6 official release and betas. Anyway, your card isn't a x16 card, it should not gives you any advantage by installing it in slot 2.