2500k, Asrock P67 Pro3 over clocking issues mult randomly changes

Once I pass 4.2Ghz with this chip, when I run Prime95 small ffts the multiplier will randomly drop. I've disabled all the power saving garbage and it still happens. The chip is water cooled temps never break 45c. I'm at a loss. Why does the multiplier just start dropping from 43 to 41 or 42. I have no problems to 4.2. Thermal shutdown is disabled. I don't know if the board is bad or something else. I had the issue with 1.50 bios, so I updated to 1.70 and it's still doing the same thing.

Is this just a voltage issue where instead of crashing the CPU just dynamically changes? If so, that really sucks. As an old school overclocker I welcome a crash as I know what the problem. I don't want some candy coated overclocking where the CPU drops speeds to keep stability.

Also, once I change settings from auto I lose the load line calibration options. same thing happened in 1.50 that happens in 1.70.

What are normal voltages for a 2500k at 4.2, 4.3, 4.4, 4.5?

Also, what are the sandy bridge defaults for vtt, pll, etc?

Here is 8 hours of Prime small @ 4.2Ghz and 1.20 volts.

looks like I may have found the answer -

http://www.xtremesystems.org/forums/showthread.php?t=264976

RealTemp 3.67 calculates the CPU power consumption number that these CPUs base their throttling decisions on.

http://www.mediafire.com/?n99nq4kn95u6i6a

The long and short limits refer to the amount of time that you can exceed these limits before you will see turbo throttling. If you can adjust the power limits in your bios higher, you should get full turbo boost without any throttling. Some software can control these limits from within Windows but it's also possible for the bios to lock these limits. If a board doesn't have these options in the bios and it decides to lock these limits then there is nothing software can do to increase these limits from within Windows.

Once I enabled speed step I had access to these, low was 140, high was 190. I changed them both to 180 and I'm stable at 4.6Ghz. 1.275 @ 4.6ghz was prime stable for a few hours, load temps just touching low 50s. 4.2Ghz was stable for over 8 hours @ 1.20v. I may not even need 1.275 for 4.6Ghz but I can back it off.

Thanks for the info. I grabbed 3.65 last night, I'll grab 3.67 RealTemp though - great app btw thanks for continuing to work on it.

so in order to use throttle stop u have to enable speedstep in BIOS am I right ?

with the asrock boards it is locked if speed step is disabled, can't speak for any others. using the extreme4 I set it to 130 short, 100 long and am stable at 1.28v 4.6Ghz with the 2500k. - 20 pass linX stable (good enough for me)