Multiplier droping and staying

[knuckleonAMD]

My AMD FX-6100@4.2ghz is having a strange problem. My multiplier is dropping down to the lowest setting and not moving back up even under a prime95 test. It only drops for some cores. Like cores 0,1 are normal at 20 but 2-5 drop down to 7. It runs for about a day then they just drop. My mosfets are cooled with a heatsink and there is alot of airflow to there. My cpu is not overheating temps are very low in fact. Cool and quiet is not enabled. What might be causing this

 

[knuckleonAMD]

Just restarted and check the bios. Cool n quiet was disabled along with everything else. Started up and all cores are back up and running full speed. I really want to know why they keep doing this.