Ok guys, thx.
The variation doesnt really alter whether under load or at idle.
Bluescreendeath, i think you have got it.
Do you think it's worth rma'ing now as it only has a year left of intels 3 year warranty or do they not cover this sort of problem/variation?
Overclocked, it rarely cracks 63 degrees under stress tests and I have ran prime95 for up to 6 hours.
Those stress temps are really fine. You should have nothing to worry about. Maybe the core temp sensors have different calibrations.