Christmas day I installed a Sapphire HD 3870 DDR4 512 gpu. I have been getting intermittent shut downs since. No artifacts or tearing, it just goes into recover mode. It is more likely to happen in gpu intensive games but will even happen while searching the net. According to CCC my temps are less than 50c under full load so I don't think it is over heating. The stock clocks are 776/1126 if I leave them at this setting I am far less likely to shut down, but it may still happen in graphic intensive applications. If I let CCC overclock in Autotune it clocks somewhere around 781/1131 (not much of an overclock at all) and will shut down VERY soon and often! When I test the overclock using CCC overclock testing it is random whether or not the over clock will pass, even if it is an autotune overclock. I am using 8.12 driver. Here are my system specs. Dell XPS 410 Windows XP Pro. 32 E6400 @ 2.55ghz. 2gb 800hz. RAM HD 3870 DDR4 375 w power supply Any suggestions? Thanks!