Originally Posted by spartacus
Set the CPU and MCH reference voltages to manual and tweak the heck out of them. (There's a certain way to do it -- I don't remember off the top of my head)
That's what did it for me when I was struggling to get 4 and 4.4Ghz stable.
He has been trying to adjust REFs. The problem is there are other things wrong with his OC that adjusting REFs wouldn't cover.
First off, as mentioned, his Performance Enhance should have been [Standard] not [Turbo].
Second, his memory timings are on AUTO but his Strap is set to 2.4B. The B strap is for <400FSB, in general.
Third, I don't think you need anywhere near 1.44vCore but you probably need a tad bit more MCHCore, maybe 1.32 or 1.34v.
Fourth, your RAM only needs 1.8 to 1.9v. You shouldn't have had to bump it as you weren't really much past it's Nominal rating.
Work out the stuff that is definitely suspect before you worry about REFs. You shouldn't need to adjust any REFs till you start going north of 500FSB.
I don't know if this will help you, but I kind of documented my attempts at getting north of 4GHz on this thread
. Read through it, there may be something helpful there for you.