mcoffey: My experience with calibrating with water is zilch but I think WoodButcher has some good advice to shoot for 3C to 4C over your water temperature. With the numbers you posted, 3 of your 4 cores would have no problem being adjusted to that level and I think even your last core will be really close to that range after adjustment. We're not looking for perfection here. The sensors aren't perfect so your idle temps won't be perfect even after a calibration. They should be very close though. Many users with 45nm Quads have had good success using RealTemp with TjMax=95C. Maybe someone running water has a good air cooler in their closet and they could run both set ups at low MHz and low core volts on the same CPU to compare idle temps between the two.

i43: Your results are very similar to what I had when testing my Q6600 on the last page. My Quad peaked at 93C on core0 and core1 and then core2 and core3 only got up to 88C as thermal throttling held the processor at this temp as Prime continued to run without any problems or crashes. I might give it some more core voltage to create some more heat next time to see what happens.

The difference between the two sets of cores is normal. I tried this test at idle with no heatsink attached and the temps across all 4 cores were within a degree or two which showed that this isn't a sensor issue. With a heatsink mounted and the CPU fan on high, the difference between cores was about 3C instead of 5C. Maybe a smart person who understands heat pipes, heatsinks and thermodynamics could explain this difference in the two sets of cores within a Quad.