z97x Gaming 7 - XHCI and USB 3.0 Help!

[rallymonkeygsx]

Hello, first time poster here.  I recently installed a z97x Gaming 7 mobo with an i5 4690, samsung evo 500gb ssd, 16gb corsair vengance ram and 2 GTX 680s running SLI.  When I attempted to install Windows 8.1 I noticed that my USB mouse and keyboard were not working when the install disc loaded up.  I then tried a Windows 7 install disc with the same results.  I tinkered around in BIOS for a while, and eventaully disabled XHCI.  This finally worked, and now my mouse and keyboard work just fine, but my USB 3.0 ports are now running at USB 2.0 speed.  I understand that disabling XHCI is the cause of this, but if I turn it to anything other than "disabled," my keyboard and mosue do not work past the BIOS.  I am running firmware F5, havent figured out how to go about upgrading it yet.  Will changing the firmware to F6 fix this problem?  Or is there some other setting that I need to try?  I don't understand why I would have to disable this feature in order to use my input devices, it doesn't make much sense.  Any thoughts?

[Manxminx]

I take it your keyboard and mouse were plugged in to the USB 2 posts?

As for XHCI, a quick Google found this interesting description from another forum:

XHCI Mode = Disabled
The on-board USB 3.0 port function like a 2.0 port

XHCI Mode = Enabled
The on-board USB 3.0 port function like a 3.0 port

XHCI Mode = Auto
The on-board USB 3.0 port function like a 2.0 port before OS USB 3.0 driver load.
If you reboot the OS, the on-board USB 3.0 port again function like a 2.0 port during this reboot BIOS phase before OS USB 3.0 driver load.

XHCI Mode = Smart Auto
The on-board USB 3.0 port function like a 2.0 port before OS USB 3.0 driver load.
If you reboot the OS, during this reboot BIOS phase, BIOS is "Smart" enough to avoid downgrade the USB 3.0 port back to 2.0 functionality before OS USB 3.0 driver load. So Smart Auto is faster than Auto on 2nd boot onward, but Enabled is fastest once you are sure the OS has the USB 3.0 driver installed, because it avoid the switching. Making the on-board USB 3.0 port function like a 2.0 port is mainly to support OS installation or to support OS that does not have build-in USB 3.0 driver, so that the USB keyboard would still work if the user plug-in a USB keyboard or any other USB devices into the USB 3.0 ports before the OS is installed with the USB 3.0 driver come with the motherboard.

taken from: http://www.tonymacx86.com/lion-desktop-support/57694-usb-3-0-gigabyte-uefi-motherboards-xhci-mode-explained.html

Ali.

[rallymonkeygsx]

Yes, the keyboard and mouse were plugged in to 2.0 ports.  It's so strange, the 3.0 ports work just fine, they just only work at 2.0 speed.  I opened a ticket with Gigabyte, but their only help is to tell me that the USB 3.0 ports are blue....