Its not a stability testing Program.
Its Folding at Home.
Folding@Home Distributed Computing
(if you want to DL it, its the Windows SMP Beta Console Client)( Or the Linux SMP Version if you want it to run on linux)
It can be used to determine if given settings are stable. But it is not specifically designed for such purpose. The program is more instense then any Program specifically made to test for stability.
A good Idea is to use Orthos or stressCPU2 to run a short test, an hour or less. If it is able to run without errors or restarts you can then have SMP Folding run for an indefinite (Amount of time to be determined by you!, but its better to have it run all the time anyways as it is assisting in medical reasearch) amount of time to determine if the OC is truely Stable.
IF any of the following things happen while SMP Folding is running, then the OC settings are not stable.
Gromacs cannot continue (Followed by Early WU end, deletion of the WU files and it then downloads and starts a new WU)
The Console closing
The four instances of FAHcore disappearing from taskmanager and CPU usage goes to 0.
I usually Let SMP Folding run for 48 to 72 hours to determine if my settings are stable. After which I try to OC more. But even then it does not garuntee the settings will be SMP Folding stable for longer periods of time.. Its simply a good indication.