Asus P9X79 WS - Turning off the Computer

2.5 Turning off the computer
While the system is ON, pressing the power switch for less than four seconds
puts the system on sleep mode or soft-off mode, depending on the BIOS setting.
Pressing the power switch for more than four seconds lets the system enter the
soft-off mode regardless of the BIOS setting. Refer to section
3.7 Boot Menu
for
details.
ASUS P9X79 WS 2-51