Originally Posted by PhilC2001
Hexa, I'm going through a similar exercise at the moment, and was wondering what your TJMax is set to in RealTemp? It seems the default setting is 98C but on my 2500k that was telling me idle temps were ~10C lower than ambient temps in my room. I don't think that is possible. Based on my reading around the net and trial & error I have lowered the TJMax value to 90C, and that seems to be more accurate.
With ambient in my room at 26.7C, my PC has been running Prime95 for nearly 6 hours now, with frequency at 47X 100MHz (4700 in CPU-Z), and the CPU temps seem to be peaking around 66C. Although I was hoping to keep around 60C, I have had to up voltage a few times to keep it stable, otherwise Prime95 was throwing Rounding Errors. Just to be on the safe side, I have set a thermal alarm in RealTemp at 72C, so if this temperature is reached it will shut the system down. There are instructions on the RealTemp web site for how to do this.
Why 72C? Because Intel states the TCase limit for the 2500K is 72.6C Intel-Core-i5-2500K-Processor-reference page.
I don't exactly know what TCase represents, I assume thermocouple temps taken at the outer case of the CPU, which likely means internal core temperature may be 10+C higher. There is a lot of different opinions on this, but I prefer to err on the safe side, so I'm aiming for lowest thermal load as I OC my PC. It would seem 4.7GHz is as far as my setup will go at safe temps, assuming it runs overnight tonight and doesn't reach the thermal alarm I have set.
You can read about Tcase here
In short, Tcase Max and Thermal Specification: Can be found on the Intel Processor Spec Finder. This is often confused by users as the maximum temperature for the cores, but in actual fact it refers to the maximum temperature that should be reached by the Tcase sensor. This specification is rounded to a relatively precise 0.1 C.
This is not the maximum temp your CPU can operate at. The maximum temp for Sandy Bridge chips is 95C, this is when the chip will start throttling back to save itself. I try to keep mine below 80C, but thats just personal preference. I know others who operate their Sandys at or above 80C every day with no ill effects. At 72C your fine.