Everything works fine except for the USB 3 controller.

The following USB 3.0 devices work fine, at USB 3.0 speeds:

ADATA C103 flash drive

Western Digital Elements SE 500 GB external drive

Mediasonic HD3-SU3 2.5" drive enclosure

The USB 3.0 controller integrated into the motherboard (ASMedia ASM1042) seems to be picky about devices under Linux.

Such devices do not work at all. dmesg gives:

usb 9-2: Device not responding to set address.
usb 9-2: Device not responding to set address.
usb 9-2: device not accepting address 21, error -71
hub 9-0:1.0: unable to enumerate USB device on port 2

The following devices presented problems:

Vantec CB-ISATAU3 IDE/SATA drive adapter (it would sometimes work if another USB device was connected first or if the connected drive was spinning first, then plugged in) - bug filed, https://bugzilla.kernel.org/show_bug.cgi?id=43279 - initially it seemed like it was the device, not the controller

Kingston FCR-HS3 flash memory reader (does not work at all)

Board able to unlock 4th core on Phenom II X3 B73 creating a "Phenom II X4 973".