I have just overclocked my AMD FX-6300 from stock speed of 3.5 Ghz up to 4.2 Ghz. However, while stress testing it will jump from 4.2 to 3.0 Ghz about every second. I have a revision 3.0 Gigabyte 990-FXA UD3 motherboard which I know is notorious for overclocking difficulties. Would that be the problem? Would it be voltage? Something I don't know about? I know it isn't temperature because I have run the CPU at 4.5 Ghz before with AMD overdrive and it got to about 65 degrees (I know that's a bit too hot, that's why I'm going for 4.2 now). It ran steadily for a few hours but I thought it'd be better to overclock through the BIOS due to an issue with Windows Aero.
Keep in mind this my first time really attempting to overclock a CPU so go easy on me here.
Probably should note that the voltage jumps from 1.3 (or whatever other voltage I set it to) to 1.1625 V as well.