when you say powernow, do you mean specifically the progrom Powernow, or do you mean just Window's control of the processor. I never used the program Powernow, but always let Windows handle it for me. Are you using the latest relesease of the AMD athon 64 processor driver (May, 04, version 18.104.22.168)? I can send you the iso of the firmware that I used. or did you use the firmware that Menator posted on his site, which I think is the same thing?