I just managed to hit 950mhz on my GTX 460 core. I can even hit 1ghz, but it's not completely stable. I'm running my vcore at 1.15v. I unlocked the voltage in my bios so that I can run up to 1.215v on the core. Here is a guide on how to do it: http://forums.guru3d.com/showthread.php?p=3839831 Please note that you may damage your card in doing this. I do not take responsibility for what you do to your own hardware.