Hi, I am new to overclocking, i've tried raising multiplier to 20ish, to get 4.0 Ghz,
but my CPU keeps throttling, it varies from 1400MHZ to 4000MHZ all the time.

I disabled C1 HPM and APM stuff like that, I cannot seem to find Cool & Quiet on my mobo.

When I'm not doing anything, CPU stays at 3700 MHZ, as soon as I run prime25, it goes to 4000MHZ, and I can observe that as soon as it hits ~50 degree, it will go back down to 1400 MHZ.

Maybe it's a temperature problem? How do I increase the max temp?

It's an automatic feature. Continually running your CPU at 4000MHZ would be like keeping your car at 7000RPM idle. It wouldn't make any sense.
Your CPU will automatically throttle when not used. When it's being used it will increase the clock.

No need to post twice about the same issue...

Stay in this topic: http://forums.d2jsp.org/topic.php?t=73251725&f=188