Asus P4P800 - Manual (Page 48)

2-22 Chapter 2: Hardware information
3. USB device wake-up (3-pin USBPW12, USBPW34, USBPW56,
USBPW78)
Set these jumpers to +5V to wake up the computer from S1 sleep
mode (CPU stopped, DRAM refreshed, system running in low power
mode) using the connected USB devices. Set to +5VSB to wake up
from S3 and S4 sleep modes (no power to CPU, DRAM in slow
refresh, power supply in reduced power mode).
The USBPW12 and USBPW34 jumpers are for the rear USB ports.
The USBPW56 and USBPW78 jumpers are for the internal USB
header that you can connect to the front USB ports.
P4P800
®
P4P800 USB Device Wake Up
3 2 2 1
+5V
(Default)
+5VSB
USBPW12
USBPW34
3 2 2 1
+5V
(Default)
+5VSB
USBPW56
USBPW78
1. The USB device wake-up feature requires a power supply that can
provide 500mA on the +5VSB lead for each USB port. Otherwise,
the system would not power up.
2. The total current consumed must NOT exceed the power supply
capability (+5VSB) whether under normal condition or in sleep
mode.