Asus ESC500 G2 - Manual (Page 46)

Chapter 3: Motherboard information 3-4
3.2 Onboard buttons and switches
Onboard buttons and switches enhance overclocking and gaming performance when working
on a bare or open-case system.
1. EPU switch
Turning this switch to Enable will automatically detect the current PC
loadings and intelligently moderate the power consumption.
For ensuring the system performance, turn the switch setting to Enable when
the system is powered off.