Asus P5L 1394 - Manual (Page 92)

4-34 Chapter 4: BIOS setup
Chassis Fan1 Speed (RPM) [xxxxRPM] or [N/A]
The onboard hardware monitor automatically detects and displays the
chassis fan speed in rotations per minute (RPM). If the fan is not connected
to the chassis, the specific field shows N/A.
VCORE Voltage, 3.3V Voltage, 5V Voltage, 12V Voltage
The onboard hardware monitor automatically detects the voltage output
through the onboard voltage regulators.