Ive been trying to break the 4.0 clock speed with my amd 965 and every thing i try over 4013 i get a bsod. processor cache failed. Have i simply reached the max potential of my cpu being that they all O.C differently or could i be making a mistake overclocking. All temps idle around 32 c i dont see temps being the issue, ram is set to oem specs.
A couple of things to try if you haven't already. Upping the NB voltage slightly or maybe even dropping the NB multiplier a notch or 2.
My 965 doesn't seem to like any CPU multipliers over 19x without throwing some major Core voltage at it. So to compensate for this I upped the FSB, which might require you to loosen your memory timings.