I have a Gigabyte HD6870 I tried to overclock it using ATI Overdrive and MSI Kombustor for testing. When I brought the GPU clock settings to 985MHz and Memory clock settings to 1120MHz id didnt complete the KMARK BENCHMARK Extreme test. SO I lowered the GPU to 980MHz and the Memory to 1115MHz and it passed with a score of 1695 at 39FPS. I then went to run the Windows Experience Index and my comp froze while it said "Running Direct3D Constant Buffer Assessment". Any ideas on why this is freezing during the Windows test but not the MSI one?