I have been experimenting with OCing an E6600 from 2.4G to 3.0+G using from 9x333 to 8x400. Std items C1E, EIST off..PCIE set to 100, and RGB set to fast, memory ratio at 2, volatge at 1.25 to 1.34 depending on the level of OC. 2G CL5 DDR2 RAM and GA965P DS3 (rev 3.3 mobo) and ASUS 8800 GTS 640MB video card and running Vista.
All that works fine... stable and definite CPU improvement in 3DMark06 scores.
The problem is that frequently (not always) when I run a check on 3DMark 06 my GPU scores almost half while the CPU is fine. For example on the very first test (can;t recall its name) in the very opening sequence when I have the computer at stock it gives me 60-65 FPS... when OCing it can drop to 20 odd! Can anyone advise what could cause this.
Dude, I have your answer. My compy was doing the EXACT same thing. And I have a cheapo 500W PSU running an OC of 3Ghz on with a 6400 and a 7900GS. Would go higher but need my SI-128 to show up tomorrow.
Anyway, up your FSB and MCH voltages by +0.1v. That should clear everything up. Did for me. Don't bother with the PCI-e voltage. Try it out and see if it works!
if everything was working fine before with the suggestion I had previously, leave it at that and don't sweat it. Other threads say to up the voltages even more but you only have to up them to cover what you're doing.
At 333Mhz FSB, you should be fine with 1.325V CPU and if the GPU is having issues, just up the FSB and MCH voltages +.1 each. Or, do one, then the other and see which one solves your GPU issue.
I know of people upping both the FSB and MCH voltages to +.3v and others upping the PCIE to 110. Your increases are so insignificant that I wouldn't even worry why they work. Just enjoy the extra oomph!