First a small rant, its not a big deal because every motherboard I have ever had, has had some sort of issue like this. When I go into BIOS sometimes the CPU multiplier will reset, and I have to manually reset it. Not that big a deal, but when I do that, it takes off my custom fan settings. So whenever I alter my bios I have to go back and forth between these two several times to make sure everything is as it should be before I save.
Ok, now onto the main topic. I use water cooling with 4 pin PVM fans. I tried to plug them into the CPU headers at first, but the processor still can get hot and the fans would really speed up without really doing anything, cool air was still blowing out and my radiator is in a push/pull taking hot air out of the case right near the exhaust. So I decided to put them on the motherboard headers. This has worked out much better, keeping the RPMs down. I have a very small mATX case, and airflow is an issue, so my motherboard hovers around 100F. I've already modded the hell out of the inside of the case but it is hard to put some good cross airflow in there. I can overclock to 4.8 with no problem on a 2600k, but the core temps creep up and it starts throttling, nothing I can do about that. The water block just can't remove the heat fast enough no matter the RPMs. I can usually get about 5 minutes of this, before it will throttle down to around 3800MHz and hover there just under 100c on each core.
Does anyone have any ideas how I can keep the temps lower? I've heard air cooling can be better but the case just doesn't have good airflow. I've tried offsetting by like .1 v to try and keep voltages down and it won't post.
Now the real issue, regardless that fan RPM is having little effect on my cooling, I cannot set it below 60% for motherboard. I wanted a quieter case. I hope they add lower RPMs for people using water cooling solutions. I've almost considered replacing with low RPM 3 pin fans and giving up on PVM.
Please let us set chassis fan RPM below 60% for those of us that watercool. Thanks.