CPU underclocking itself?

[uhh3000]

I'm using an AMD Phenom II x4 965 BE and had a stable overclock of 3.9 ghz @ 1.5v. Even after 14 hours of Prime95, it stayed stable and never exceeded 58 degrees. However, I noticed earlier today on CoreTemp that every core was said to be at a mere 200 mhz. Perhaps it's a mistake with CoreTemp readings, because I noticed no lack in performance whatsoever and my bios read 3.9, but this still worried me. I put it down to 3.6 ghz and 1.475v and everything seems fine, coretemp is reading it correctly and whatnot. Has anyone else ever experienced something like this with this cpu, or has anyone ever had an issue like this with coretemp? btw, my motherboard is the ASrock 970 extreme4

 

[socialfox]

Well just a guess, I have the 955 BE and when I had Cool'n'quiet on my processor clock speeds per core was at 800mhz. This was at idle, when at load it would step back up to the stock clock of 3200mhz. Either way if this is an overclock, I would advise to turn off Cool'n'quiet.

 

[steddora]

+1 to what socialfox said! That Cool'n'quiet ability is a pain in the butt.

I'm not sure with the 955 BE, but some motherboards have the ability to control the power of the processor. Sometimes if your processor exceeds the maximum allowed power it will actually drop the speed of the processor to be acceptable to the limit. For example.. My 2600k@4.4Ghz will pull around 120w of power at full load. If my board was set to 110w it would actually drop the multiplier to 40 or so to keep from exceeding the maximum TDP of the motherboard. Now setting the max to 130 fixes that problem. Maybe you should check into that as well.