Every
CPU has different
GTL ref +
VTT requirements, so there's nothing I can tell you that will help you get there, you need to experiment and see what works for
your set up.
45nm quads are often not very good overclockers, meaning that they can be
FSB limited. If you read back in many of the T3RS/T2R threads, you'll see many people with the same problem. The only real way to get round this is with a DMM and measure your voltages manually, but even then, there's no guarantees.
I'm sorry that I can't be more specific, but it really is a case of experimenting and finding out.
Linear Mode
