clokker: You need to show me a couple of screen shots at idle and full load with RealTemp including the settings window opened up beside CoreTemp.

I believe that OCCT offers you the option to select from a multitude of sources for temperature data including it's own internal source. I'm not sure which sensor or program it is reading data from in your screen shot.

With no idle calibration, the difference in displayed temperatures between CoreTemp and RealTemp should be exactly equal to the difference in TjMax that they are using. It's possible to change TjMax in most programs today so I need to see some more data. By default, for the 45nm chips, RealTemp uses TjMax=95C while most other programs are using TjMax=105C.

Reported Temps = TjMax - DTS

It should be easy to see how changing TjMax directly effects your reported temperatures. The reading from the digital thermal sensors (DTS) should be consistent between RealTemp and CoreTemp.

JVM: If you are happy with your displayed temps then be happy. If you want to try to get another degree or two more accurate then read the documentation and try doing the calibration. From what you've said, your temps are probably pretty close as is. Temps aren't too important anyhow. As long as your computer is running stable then there's nothing to worry about.