Stress testing CPU using Prime95

Download prime95 and RealTemp and extract them to a location where you can easily find them.

Run RealTemp.exe



The top window section will have your CPU info(model no.) | Core clock | FSB x multiplier.
The load and time you have been running RealTemp below that.

You will find TJ Max in several places. And after searching the web, you will find a few definitions for the term.

TJ Max which is the safe maximum operating core temperature for the CPU. As your CPU heats up, your Distance to TJ Max will decrease. If it reaches zero, your processor will start to thermal throttle or slow down

TJ max is the maximum allowable temp for a processor's internal cores, if you reach TJ max the processor's THERMTRIP# signal will activate shutdown to prevent damage to the processor.

Your goal is to stay away from TJ Max and maintain as great a distance as you can.

RealTemp has a Sensor test that will check your processor's distance to TJ Max with regards to temperatures at varying load.

This will give you an idea how much load your processor can handle before overheating beyond recommended temperatures.

Click on 'Sensor Test'

A new window will pop up. Click on start and browse to wherever you extracted prime95 and click Open.

Select the second option. 'In-place large FFTs'

The Heat Up Phase will begin where the load will increase to 100% and this is where you keep an eye on RealTemp's main window:

Check your maximum and minimum temps in RealTemp after the test has completed. If you have an old CPU with a stock cooler, you will get temps like this.

You can follow the common solutions to overheating in the page I linked to earlier to lower these temps. Remember: Lower the better.