First off Download CPU-Z - Realtemp -Prime95 - I recommend running a stability test such as Prime95. Another great one is LinX which is very intense. You can run it as long as you want and there are many different opinions as to how long you should run the tests to do some research online and make your decision.I usually start with IBT because it tends to find errors MUCH more quickly than Prime95. After it passes an hour or so of IBT, I run LinX for two hours.I run Prime95 blend for many hours (usually 10 to 12). I don't think any single program is conclusive though. I've had overclocks that pass Prime95 and not IBT, or vice versa.
OCCT is the best for GPU testing. It will run your GPU far hotter than any game, so if you pass OCCT you should easily be able to handle games.Unigen Heaven 3.0 is good as well.Check these links out as well
http://www.majorgeeks.com/page.php?id=39 and this
http://www.majorgeeks.com/page.php?id=43 Futuremark is a software company which offers a wide variety of computer benchmarks which are considered among the best in the world. Chances are that any review of a desktop or laptop computer you’ve ever read has, at some point, quoted 3DMark or PCMark figures in the performance section of the review.
The latest versions of 3DMark and PCMark aren’t free, but older versions with limited options can be used an unlimited number of times without charge. While these benchmarks are over four years old, they are still among the best free benchmarks available. Futuremark’s benchmarks are very demanding, and there are many modern computers which will achieve very low scores when running these benchmarks.
3DMark focuses on gamers, has it only tests the power of your video card. PCMark is for more general use and tests numerous computer components. Both can be downloaded directly from the Futuremark website.