Is this CPU throttling?

[ipb]

I got a new cooler and I started overclocking, but I ran into this problem:
http://store.picbg.net/pubpic/4E/AC/c955369f33d24eac.png

It works fine for the first couple of minutes, but after some time it starts doing these strange drops.
The Task manager shows a drop to 30%. HWiNFO shows the cores at 100% all the time, but at the moment of the drop, they are working at 1.4ghz. Also Task Manager never shows 100% Cpu usage, always arround 88-92% and also it never shows the cpu at it's max frequency of 4.3ghz, but instead it's at 3.8ghz. HWiNFO is displaying the utilization and frequency correctly, but there are frequent short drops in frequencies of individual cores. Is all this normal?
Currently I've clocked it at 4.3ghz, 5ghz turbo mode and +200mV.

 

[st3v30]

Disable turbo core cus it will never hit 5 Ghz and it mess with your OC.
Which mobo do you have and which cooler?

 

[GhislainG]

It depends on your motherboard. Is it good enough for an overclocked FX-8320 that could draw significantly more than 125W? Checking the temperature isn't that useful with an AMD CPU; did you make sure the thermal margins (use AMD Overdrive) are in the double digits at full load? At 0°C it will throttle, but a motherboard with unsuitable CPU VRM that gets too hot will cause the same issue. An AMD 8 core FX CPU has to requires a quality motherboard.

 

[ipb]

Actually it hits 5ghz and it's a great increase in single thread performance. My motherboard is Gigabyte 970A-DS3P. I haven't used AMD Overdrive. I overclock from BIOS

 

[st3v30]

Try without turbo core and see how it goes.

 

[teknobug]

That's a good motherboard, but whew 5GHz turbo? Try toning that down to see what happens, sounds a little like temperature throttling.

 

[ipb]

I disabled turbo but this still happens. HWiNFO shows that temperature peak is 68 degrees celsius so I guess it's throttling. My cooler is gammaxx s40 and I though it would handle clock of around 4.5ghz, but I guess I was wrong. I will make some tests at 4ghz to see if this happens again. It's the middle of the summer and the room temperature is pretty high, so I guess this contributes also.

 

[st3v30]

I think with gammaxx s40 max safe will be 4.3 Ghz.
With my HR-02 MACHO REV. B i can get safe temps even on prime95 26.6 SmallFFTs test and my room temp is around 27°C, but my cooler is much bigger than gammaxx s40.
So dont push too high.

 

[GhislainG]

That's a good motherboard, but whew 5GHz turbo? Try toning that down to see what happens, sounds a little like temperature throttling.

That motherboard isn't good enough for an overclocked FX-8320 CPU and the VRM causes throttling. The GA-970A-UD3P is a much better motherboard.

 

[teknobug]

An 8320 on a 970A-DS3P should get to 4.0-4.2GHz, 4.5 is still a bit high. I've OC'd an 8320 on a 970A-DS3P as well (and a 970A-D3 rev3) but didn't try going over 4.2GHz.

But the 5GHz turbo kind of shocks me.