The manual states that the default position of this "CPU Over Voltage Jumper" is in positions 1&2 (Disabled) . If you place the jumper in position 2&3 (Enabled) it will set a higher CPU voltage for Overclocking? Now does that mean if you boot up in the Enabled position that it automatically applies a higher voltage to the CPU or does that mean that it ALLOWS you to apply a higher voltage to the CPU via BIOS Configuring?
Enabling the overvoltage jumper shouldn't apply more voltage, it should let you use higher voltages.
Enable for extreme overclocking, for normal use and mild overclocking let this disabled.