I had a problem with my new build using this motherboard and a 3770k i7. for me the usb3 on the back of the machine would only work IF I had something plugged into it and then booted the machine from a cold boot. Then if I let the pc sit long enough for the monitor to shut off, the usb 3 superspeed controller would be GONE!! What I did was go into the Bios and found the xHCI controller and changed the setting from AUTO to ENABLED... problem solved. just thought I would post this here for others to try since it seems to be a HUGE problem for many people.
