Prime95 is more for people that want absolute stability. I think that if your PC can survive a Sandra burn in test for a couple hours, then it should be plenty stable enough. If you want a real representation, just go play your favorit games for 10 hours straight. If it doesn't crash, then it should be fine for what you are planning to do with it. You also have to remember that certain benchmarks stress certain components. There is only one real benchmark that can test your graphics stability after you overclock your graphics card. That is 3DMark. I think you should decide on your own what you think is stable. Worse comes to worse, if it keeps crashing on you while doing the things you do on your PC, then clock it down a little.