Laptop Lenovo W520 with 2 USB 3.0 ports.
I have issues with the "Renesas USB 3.0 eXtensible Host Controller" which got installed automatically with Windows 8. When the device is marked as working in the Device Manager (no yellow triangle on the corresponding icon), the USB 3.0 ports work, but only if both of them aren't in use. If i try to use both of them, either ports stop working or they do so very sluggishly - using a mouse is a chore.
Sometimes, after a reboot, none of the ports work and the "Renesas USB 3.0 eXtensible Host Controller" is marked with a yellow triangle in the device manager. Log info says, that the device has stopped working.