i am having problems with stability (game crashes, artifacting) and ntune for some reason no longer enables me to do a stability test (it says the test is in progress but i no longer see those wierd figures dancing around) . i want to see if its my card that has a prob or something else in my system. ive already tested my memory and my cpu and they both seem fine. im using ati tool right now to test my gpu. now my question is, how long should i let the artifact scan run, before i can be reasonably sure my gpu is stable? ive done some searching and i get a range of anywhere from 20 minutes to many hours. so for the atitool users here, how long do you run the scan for? also is atitool a good utility for gpu stability testing? what do you who are better informed than me recommend?