Asus M4A78-HTPC/RC - Manual (Page 39)

6. USB connectors (10-1 pin USB56, USB78, USB910)
These connectors are for USB 2.0 ports. Connect the USB module cable to any of
these connectors, then install the module to a slot opening at the back of the system
chassis. These USB connectors comply with USB 2.0 specification that supports up to
480 Mbps connection speed.
Never connect a 1394 cable to the USB connectors. Doing so will damage the
motherboard!
The USB 2.0 module is purchased separately.
7. Audio power connector (4-pin Audio_PWR)
This connector is for a 4-pin power plug from a power supply. Connect a power plug to
this audio power connector for better sound quality.
Do not share the same power cable with other devices to reduce the electronic interruption.
Chapter 1: Product introduction 1-27