A: Motherboards with USB 3.0 might have a xHCI configuration. It controls how the USB 3.0 ports behave. I prefer to set mine to Enabled, so USB 3.0 ports always act as USB 3.0. It seems to avoid some problems I have seen on systems. Here are the setting choices and what they do:
Disabled - USB 3.0 ports behave as USB 2.0 ports.
Enabled - USB 3.0 ports behave as USB 3.0 ports.
Auto - USB 3.0 ports function as USB 2.0 ports until the OS USB 3.0 driver loads, at which point they function as USB 3.0. If the machine is rebooted, the ports revert back to USB 2.0 until the OS driver loads again.
Smart Auto - Same as Auto, except during a reboot the ports aren't downgraded to USB 2.0.