Then check your Temps if it gets to hot it will throttle it down to 800 mhz or 852 in your case since it is overclocked. Use real temp or core temp to see how hot your CPU is getting. Are you overclocking on stock heatsink?
No I have a different cooler.... what temp will it throttle down at?
Whatever it is set in the bios to throttle at usually around 80 or 90 it will throttle.
You need power saving features disabled in Vista/Win7 in some cases along with turning cool n quiet off in the bios for it to actually turn off.
It throttles down at like 55 and power setting is right.