Asus P5N-EM HDMI - Manual (Page 101)

ASUS P5N-EM HDMI A-3
8. On the Power schemes section,
click , then select any option
except Home/Office Desktop or
Always On.
9. Click Apply, then click OK.
10. Close the Display Properties
window.
After you adjust the power scheme,
the CPU internal frequency slightly
decreases when the CPU loading is
low.
The screen displays and procedures may vary depending on the operating
system.