I have the HR03 Thermalright cooler, and great case airflow. My card came company overclocked. Pny 8800Gtx OC. 621/1000 i think. I have been able to reach 633/1066 via ATI Tuner. Any higher and my screen automatically locks up. Is there a way to continue to push my GPU? or is this the limit. Can you increase voltage to the PCI E ? Maybe I should be using a different Overclok Utility...? I am pretty sure I can reach higher clocks, espescially with such a nice cooler....keeps my Card Idle at about 45 and at load it never gets past 60-65C Any help would be appreciated...It should be known that If iI cant get it any higher...I will be able to live, It's not a huge deal, Just want to see If i can push it more. Thanks!