Pentium® III Processors Voltage Requirements

Pentium® III processors are specified to operate at the voltages provided in the table below. It is important to verify that the motherboard explicitly supports the specific processor (by stepping and speed).

Voltage Requirements for Pentium III Processors

Core Speed Core Voltage
Minimum Nominal Maximum
450 MHz 1.93V 2.00V 2.07V
500 MHz 1.93V 2.00V 2.07V
500E MHz 1.52V 1.60V 1.64V
533B MHz 1.98V 2.05V 2.12V
533EB MHz 1.57V 1.65V 1.69V
550 MHz 1.93V 2.00V 2.07V
550E MHz 1.52V 1.60V 1.64V
600 MHz 1.98V 2.05V 2.12V
600B MHz 1.98V 2.05V 2.12V
600E MHz 1.57V 1.65V 1.69V
600EB MHz 1.57V 1.65V 1.69V
650 MHz 1.57V 1.65V 1.69V
667 MHz 1.57V 1.65V 1.69V
700 MHz 1.57V 1.65V 1.69V
733 MHz 1.57V 1.65V 1.69V
750 MHz 1.57V 1.65V 1.69V
800 MHz 1.57V 1.65V 1.69V
800EB MHz 1.57V 1.65V 1.69V
850 MHz 1.57V 1.65V 1.69V
866 MHz 1.57V 1.65V 1.69V
1.0 GHz* 1.62V 1.70V 1.74V

* Note that 1.0 GHz = 1000 MHz

Proper voltage must be supplied for reliable operation. It may be supplied by a regulator integrated in the motherboard, or by a voltage regulator module (VRM) installed in Header 8 on the motherboard.

If the regulator is integrated in the motherboard, it must be Voltage ID (VID) programmable to allow the processor to program the correct voltage during power-on.

If the motherboard has Header 8, then a VRM must be installed in the header to power the processor. Most VRMs are VID-programmable. If your motherboard has a fixed-voltage VRM, its output voltage must match the processor requirements.

Since the operating voltage of Pentium III processors may be changed as the processor goes through stepping changes, VID-programmable voltage regulators are the preferred solution.