2500K with Corsair H60 on ASRock P67 Extreme4

[Airmantharp]

I've recently completed my Sandy Bridge build, and am starting to overclock the processor.

First results using the stock cooler had the CPU comfortably running at 3.6-3.7GHz under Prime95 load, and first results with the H60 have it running at 4.0-4.1GHz. The ASRock board is currently 'auto' overclocking the CPU, as I have it set to boot the CPU at 4.8GHz with automatic adjustments for voltage and SpeedStep. This results in the CPU running at 4.8GHz on the desktop during brief loads, but throttling down to the above 4.0-4.1GHz during sustained loads.

My goal is to get it running at 4.5GHz or more under sustained loads, keeping voltage as close to stock as possible and not exceeding 110% of stock voltage.

My secondary goal is to get this thing quiet. The H60, while fairly quiet, is now the loadest part of my system- I think that the intake filter I put on it is adding to it's noise profile, but I'd like to see if I can't get it to lower it's fan speeds. I'll have to balance heat output and fan speed to keep it stable; that's what I'll be discussing in the future as I have more opportunities to work on it!

[Airmantharp]

Small update:

While trying to work out other issues, and considering a motherboard change, I've gotten the CPU running at 5.0GHz mostly stable. It eventually fails but so far has always done so while I've been at work or asleep and I can't be sure what the point of failure is, but I know that it can handle hours of Bad Company 2 and Dragon Age II without crashing.

For reference, my overclocking stability test consists of a Prime95 maximum heat/power draw load for the CPU on all four cores, with Furmark loading the two GPUs. So far my Kill-a-Watt has shown about 550w under this load which should be around 500w internally accounting for the PSU's 90% efficiency.

The Seasonic X650 Gold PSU gets just barely warm without making a peep of noise in this situation, by the way. So yes, for you over-achievers out there that like to put 850w and 1000w PSUs in your builds just to feel 'safe', maybe you feel safe but you are wasting money too!

The motherboard change I'm considering is to return my P67 board and move to Z68, as I purchased Cyberlink's MediaEspresso software which can take advantage of Intel's transcoder engine, and because I'm considering an Eyefinity setup so I would like to move my 'monitoring' monitors off of the Crossfire team to the Intel GPU, as they won't be part of the rendering setup. The only issue I have is that the board I would want would be the Extreme6 version from ASRock, which doesn't appear to exist yet; the version they have for P67 is perfect for my needs except for the lack of video output and access to the transcoder engine.

[Airmantharp]

Next small update:

ASRock's UEFI has fan speed step goals and CPU temperature goals. I had originally set it to 60c and step 5 across the board, but found that the computer was very loud even at idle- I've just now gone back in and set the CPU temperature goals to 65c and the fan speed steps to 1 across the board. Since the UEFI tends to idle the CPU at <1v and 1.6GHz, this is stable and very quiet through post to the desktop, though I'll be doing some work to drop the noise down another notch or two; I still have a handful of inline fan resisters and have the fan controller maxed out with the bottom fan and two top fans.

When I run Prime95 with a maximum power draw load, the fan on the Corsair H60 slowly spins up (somewhat like a jet engine...) from around 850RPM to 1800RPM and the CPU heats up to unknown heights. Prime95 doesn't crash, and neither did Dragon Age II with all settings maxed and 4xAA for a couple of hours, and I'm pretty happy with the results so far. Next up is to limit the UEFI's voltage range, as it's going up to about 1.38-1.4v according to Speedfan, and I'm not comfortable with that for the long haul.