I've run prime95 before16 hours, no issue. I run more graphically-intense games very often, with no issues. I've also run FurMark, however, 600+ series shut down when they hit a certain temperature. I honestly think it's something to do with software, not hardware, but I've tried the latest beta drivers, the latest signed, and a variable roulette of past drivers at people's recommendations. Was hoping someone would have an answer.