Spacehead: I've been banging my head against the wall for the last year trying to convince people that the data coming out of the DTS sensors does not change linearly with changes in core temperature, especially at idle. Your post confirms that. Head to the first post in this thread and have a look at the nice graph I created to help explain this. My E6400 - Revision B2 does the exact same thing as your E6600. It reports idle temperatures that are too low and impossible to achieve.

Since developing RealTemp, I have not put my E6400 back in for an in depth study but I can say the (++) Idle Calibration setting was developed with my E6400 in mind. Using that setting should get you very accurate temperatures from Idle to TjMax at 85C and even beyond that. I just released v2.21 yesterday with a couple of bug fixes which should correct some issues that KTE discovered during his recent high temp testing between TjMax and thermal shut down.

Why don't you do us all a favor and drop your MHz down to 266x6=1600 MHz and drop your core voltage down to 1.10 volts and show us your idle temps with no calibration correction and then with a (++) correction. After correction your idle temps may not be perfect but they should be a lot closer to reality.

Maybe I'll do a thorough test of my E6400 similar to the one I just did with my E2160 while waiting for my Q6600 G0 to arrive.