The USB 3.0 port has a problem that may be caused by some software corrupting the driver (or the driver is poor). I got two USB 3.0 drives for storing backups but the write speed drops from 66 mb/s to unusable (1mb/s) every second or third use. The "fix" is to uninstall the USB drivers (Device Manager) and reboot. Using a USB 2.0 drive also works. (The drives work fine on an old laptop with USB 2 ports.) I keep checking asus.com for an updated driver but none so far.