I would like to know if there are some reliable programs that I could use to test the performance of the video ram. I have been using techtool deluxe to test performance on my mac pro, but since I upgraded to snow leopard it keeps giving me odd results testing my video ram with the new gtx285 video card. Sometimes the test passes and sometimes it fails. I am worried that the gtx card may be faulty, or some other part of the system affecting video ram may be faulty, although I am seeing no symptoms of any graphics problems or any problems of any kind on the machine. I upgraded techtool to the latest version that supports snow leopard but it's still not consistent. I installed snow leopard over leopard, and haven't had the time to do a complete fresh install of my new os and all my software. Thanks for any advice.