Question about relationship between OC'ing and PSU

[faromic]

First, here are my computer specs:

EVGA 680i mobo
Intel E6600 2.4 GHz
Zalman 9700 HSF
2GB Super Talent PC6400 RAM
EVGA 8800 GTX Video Card
PC Power and Cooling 750 W 750EPS12V PSU

When I try to OC my CPU (even to 2.8 GHz) it gets really choppy. I know my PSU has one 12V rail and am not that knowledgable on PSU's, so I guess my question is whether the PSU has a huge effect on the OC of teh computer? When I OC'ed, I manuall set the timings. Could the memory timings cause this? What is the advantage of 2 12V rails?? I should be able to get a good OC with the HSF and setup I have. I just don't get it.

 

[delluser1]

It's not the psu, maybe if you were using the Silencer 470, but the 750 is a monster that overclocking won't bother.