I'm running a q6600 on a Abit ix38 quadgt. The processor is clocked at 3.2ghz (9x356). Temps have been 19c idle (18c ambient) and never above 38c load. My concern is that cores 0 & 1 are runnning about 9c greater than cores 2 & 3 at idle. Under load, all core temps stay within 6-8c of eachother. I do not feel this is normal but I would like some opinions Been trying to research CPU VTT (set @ 1.24) and CPU GTLREF (set @ 67% for both 0&2 and 1&3), exactly what do these controls do? I have found limit info but I'm still not quite sure if the CPU GTLREF is what is making the temp difference in the cores as this is the default setting in my BIOS. The "Core 2 quad and duo temperature quide" states a core offsets of up to 5c are normal for quads... I seem to be well outside that and I'm wondering if there is anything i can do about it before i try some potentially costly trial and error runs.

3.4ghz has not been stable enough for Prime95 and requires >1.4V at CPU (which makes me nervous for somereason) and much tweaking, but system runs flawlessly in Prime95 for hours at 3.2ghz with 1.35V (four instances of prime95).

To restate my initial question: Is the core temp offset a problem? what can i do to fix it? Also, what do CPU GTLREF and CPU VTT do and how are they related to eachother, if at all?

Thanks you all for your time!

EDIT: I'm using abit uGuru and SpeedFan 4.33 for all temp and voltage monitoring.

In another thread, someone was experiencing similar problems. Something like 11C difference under load. This could entirely be uneven contact area between the cpu and heatsink, or the difference in location of the sensors.

As long as the hotter core doesn't get to hot, I see no problems. If you are truly worried, you can lap both your cpu and heatsink. There's a guide on them here.

For your overclock, it could be your ram. Run the blend test in prime95. If it gives you error, you may need to lax timings and/or raise voltages for the ram.

I think you are probably right, evilonigiri. Perhaps the thermal grease spread more in one direction and covered some of the cores better... who knows!

I just reached a stable 3.4ghz and the hottest core reaches about 62c under full load. Heat doesn't seem to be an issue so maybe i'll just forget about it.

My ram is not the nicest stuff. I have it running just under 800Mhz @5-5-5-15 which is stock so i figure that's fine, although I did bump the voltage up a bit to help the OC... I'll tweak it down as far as i can later