do you have APM in your bios options, disable it.
I had fluctuating when under load with my 8320 and it was the cause, not any of the other power saving features.
APM tries to save power when under load.
also if you have a "turbo boost" you may want to disable that too when you start OCing, it gives a boost of like 0.5 for 2-4 cores on occasion, but it jumps volts up to 1.4, its unlikely you need that much voltage for the increase so its just extra heat/power used.
and HPC, that makes your cpu run at 100% clocks, all the time even when idling, web browsing, anything, which honestly makes me not a fan because of the extra power used thats not needed, and the extra heat, but I know some have had success with it.