[SOLVED] fx 8150 overclock problem

[spoilsport]

As you see in the screenshot core clock going down periodly.
This happen when i overlock my cpu to 4.2 ghz or higher. 4.00 ghz is ok. i tried to give some voltage but it gets worst more dip happens.
Why is this happening ?
motherboard GA-990XA-UD3
cpu fx 8150
8gb ddr3 cl9 1333 mhz ram

 

[Calvin7]

Memory is at slow speed.

 

[Karadjgne]

That's doesn't look like 'small fft' torture test, which is 100% clean load. Instead that looks like a blend which uses intermittent ram usage and drops the load on the cpu as a result. That's the down spikes. As you see it's topping out at 4.23GHz but at the actual time of reading the cpu happens to be at 4.08GHz.

Or if in fact that is small fft, you maybe suffering from overheated/failing VRM's or a really crappy psu that cannot supply a decent voltage under duress.