CPU Stress Test Programs?

I was wondering what programs I can use to do a stress test to check if my current overclock settings are stable.

Currently I have AIDA64 installed but it is the trial version. Is it okay to use this synthetic to maximize the CPU for lets say, 5 minutes, that way I get an idea of what the max temps will be. Or should I use something else since this is the "Trial" version. It doesn't seem like I am being neglected of features of this program though.

Also to clarify, from what I understand of a synthetic stress test, this is more than likely going to be more than what I use everyday on the computer. So should I be using a synthetic just to test max temps? And if it passes without crashes during the test run, then I should start running programs that I normally use correct?

 

Sorry if these are not good questions. This is my first time manually overclocking my CPU.

Aida64 is a good stress test. You need to test for MUCH longer than 5 minutes for stability. Temps need about 30 mins - 1hr to fully equalize. Stability I test for 5hrs+. 

OCCT is great

Thanks for the info from both of you!