How do I run a stability test?

[GraySkies]

I strongly suspect my NVIDIA GeForce GTX 560 Ti is dying on me. To that end, I grabbed Furmark with the intention of running a stability test...but there doesn't seem to be an option to do that in the user interface. I see benchmarks but no stability test. How do I set up a stability test, and what should I be aiming for as far as length of time, settings and so on?

 

[RobCrezz]

Just let furmark run for a while, see if it crashes or not.

Unigine Valley is another good one Ive used for stability testing.