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.