To undervolt the processor the process is very simple and only one BIOS setting needs to be changed to undervolt just the processor. After hitting the delete key while the system was posting we were able to get into the BIOS. After going to the System Voltages page, under advanced settings, we were able to reduce the CPU voltage from 1.35V down in whatever we wanted thanks to the 0.025V adjustments found in the Foxconn BIOS.
While lowering the voltage on the processor we ran stability tests to make sure the processor was 100% stable at these lower voltages. We ran a combination of stability tests, but stuck mainly to 3DMark2006, Super Pi and Prime 95. A quick and simple way to test stability of a dual-core AMD X2 processor is to run two instances of Super Pi at one time.
We also ran Prime 95 overnight and many Super Pi tests to 32 million places while doing other activities on the desktop to make sure the test system was rock solid.
After running our test system through 72 hours of torture testing we came to the conclusion that 1.125V Core was the lowest voltage the core could do with 100% stability. At 1.100V the system would crash while stability testing and at 1.075V Windows XP Professional coudln’t get past the splash screen.