"After reading the little voltage trick over at HardOCP on how to modify a Cel-II to get it started out at 1.65v, it made me start to think what I could do with my PIII-550. Let me give you a little background on why I did this mod then I will tell you what I was able to accomplish.
First, the board that I have my PIII-550 running in is a Soyo SY-7VCA that is an AWESOME board and pretty darn cheap (PCNUT has them for sale for $110), the only problem is that I got one of the very first boards (only like the first 20 boards shipped out had this problem they said) that was missing a resistor that somehow was related to the voltage tweak in the BIOS. Whenever I tried to up the voltage on the board the actual voltage wouldn't change & the system would become very unstable. So I always had to use the default voltage for the CPU (which for the PIII-550 is 1.6v). I was able to run about 141FSB (776Mhz) on it with a single 128MB DIMM, but when I stuck in two more (all 3 DIMM's now full with 128MB PC133) the system would only run stable at 133FSB (733Mhz). This was all fine and dandy, but after I say the article on HardOCP it made me start to wonder what I could do with my CPU. Well I went to the Intel website and found the spec's for the PIII's."
FULL STORY @ EXTREMEOVERCLOCKING (http://www.extremeoverclocking.com/articles/howto/CPU_Voltage.html)