There are four standard USB 3.0 ports on the rear of my board.
Ports 1 and 2 work as expected. Ports 3 and 4 only detect one out of the four USB 3.0 devices I've tried, and that one device that was detected was forced to run at 2.0 speed. The other three USB 3.0 devices were not detected, and didn't even appear to have power. All the 2.0 devices I tried work on all ports ports.
I've checked the ports and there are no physical abnormalities.
I can't find anything in the manual about those USB ports having 3.0 functionality disabled (to free up PCI-E lanes or something), but even if that were the case, it wouldn't explain why the other three 3.0 devices wouldn't work even in 2.0 mode.
Is the board faulty?