Asus P5Q3 Deluxe/WiFi-AP @n - Manual (Page 44)

2-20 Chapter 2: Hardware information
2. CPU / Northbridge overvoltage setting (3-pin OV_CPU, 3-pin OV_NB)
These jumpers allow you to enable or disable the advanced CPU and
Northbridge overvoltage settings in BIOS. Read the following information
before you change the jumper settings. Set to pins 1-2 to activate the
advanced CPU / Northbridge overvoltage feature.
• Before you change the jumper settings for extra-high overvoltage ability,
use the BIOS items first to adjust the desired CPU and Northbridge
performance. Make sure your system functions well under the highest BIOS
voltage settings before you change the setting of these two jumpers.
• DO NOT set the OV_CPU jumper to pins 1-2 when you install a new CPU
and have not booted for the first time. Doing so may cause the system to
halt. For system failure due to the wrong setting of the OV_CPU jumper,
shut down the computer and move the cap back to pins 2-3.
• The system may need a better cooling system (for example, a water-cooling
system) to work stably under high voltage settings.
OV_CPU OV_NB
Pins 2-3 (Default) up to 1.70V up to 1.91V
Pins 1-2 (OV Enabled) up to 2.10V up to 2.21V