Prime95 is my favourite for sniffing out weaker Cores/Modules.
It's difficult to use at higher clocks though as it works the CPU 15% more than other programs. It pushes you over the 145A limit with the 130% Current setting, and causes a fail.
CSSORKINMAN - is right about OCCT, the graphs are invaluable.
Edited by ComputerRestore - 1/15/13 at 9:11am