Asus M5A99X EVO User Manual page 41

3. USB 3.0 connector (20-1 pin USB3_34)
This connector is for the additional USB 3.0 ports, and complies with the USB 3.0
specificaton that supports up to 480 MBps connection speed. If the USB 3.0 front panel
cable is available from your system chassis, with this USB 3.0 connector, you can have
a front panel USB 3.0 solution.
ASUS M5A99X EVO 2-23