Hi,
Which "flavor" of that mainboard do you have?
I've got an P8H67-V, using the Renesas/NEC driver from multibeast the USB 3.0 jacks worked before. Due to lack of USB 3.0 devices I have tested them using USB 2.0 devices only, but the driver handling the 2.0 and 3.0 accesses are the same, so 3.0 should do as well.
Best regards,
Daniel