I recently built a new computer with 2 Zotac GTX 460 in SLI. Up until a few weeks ago I hadn't really done much gaming so I really never noticed a problem. However, now that I am gaming, it's clear that there is some kind of problem going on. If I'm running in SLI after about 10-20 minutes of gaming the computer locks up and starts stuttering and eventually I just have to hold the power button to shut it down. What I noticed is that when this was happening, the GPU fans were running a million miles per hour. This led me to believe that it might be an overheating problem, so I downloaded afterburner to try and monitor what was going on which led me to the source of the problem. GPU 2 is considerably hotter than GPU 1. At Idle GPU 1 : 37C - fan speed 20% GPU 2 : 44C - fan speed 20% Heavy Load GPU 1: 62C - fan speed 23% GPU 2: 85C - fan speed 65% Also, GPU 1's temp rise is much more gradual and looks like a smooth hill where as GPU 2's graph has huge peaks. Here is a picture Any idea what's going on?