I gather there is a standard thermal diode (STD) for the CPU in general and a digital thermal diode (DTD) for each core. Programs like Asus Probe only read the STD. Programs like Everest and HWMonitor read both. For the Q9450, you should be worried if the STD reading exceeds 71C according to Intel.Core Temp, Real Temp, Everest and HWMonitor use the DTDs to get more accurate temperatures at the core junctions, however, AFAIK, Intel has not issued any recommendations regarding healthy thresholds in this regard. All we seem to know is that the CPU will throttle down when the "delta" approaches zero or the core junction approaches TjMax.Core Temp claims to read TjMax (105C in the case of the Q9450) from the CPU itself. Real Temp appears to arbitrarily set TjMax to 95C by default in order to achieve a temperature closer to the STD temperature which really makes no sense IMO. Both programs are getting the same "delta" reading from the CPU. Personally, I ignore the DTD temperatures (unless there is a significant disparity between them) since invariably the STD reading is going to "hit the fan" first. Rebuttals and differences in opinion are welcome since the above is just my take on "much ado about nothing". Besides the ability to pinpoint a possible issue with a single core, these DTD reading programs have provided more confusion than enlightenment IMO.
The temperature monitoring software that I will be using is Real Temp 2.60 as it reads all four cores, documents the maximum temperature for a period until you reset it and most importantly reads the 45nm processors tempeartures correctly.