Asus P9X79 PRO - Manual (Page 49)

ASUS P9X79 PRO 2-29
Chapter 2
4. USB 3.0 connector (20-1 pin USB3_56)
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.
You can connect the ASUS front panel USB 3.0 box to this connector to obtain the front
panel USB 3.0 solution.