Overclocking CPU idles high - fans not working right?

Not open for further replies.


Posts: 6   +0
Hi everyone,

New to the forums here, so thanks to everyone up front:

My i5-750 that I OC to 3.5 ghz idles at about 37 - 43 C using RealTemp. My Lian Li case has a large fan in front blowing air in, two on top sucking air out, and one in the back also sucking out air.

I have a Noctura fan for the CPU with both fans, one pushing air in and one sucking air out, so I'm thinking my CPU should be quite cool. No matter what, my fan speeds
stay the same. I use the ASUS Fan Expert, and tried SpeedFan (or something like that) but my RPMs for the fans stay the same. I'm thinking I don't have the fans
plugged into the right fan ports on the MOBO. I should be able to increase the speed of the Noctura and the main fan in front, right? When I turn on turbo on FanExpert absolutely
nothing happens. In BIOS, all the fan settings are set to enabled. I'm really at a lose here. Could it be that PSU isn't strong enough?

Any help would be greatly appreciated !!!

BTW: My entire system I built about 6 months ago.

Thank you all

Lian Li case, W7 64-bit, ASUS P7P55D-PRO, i5-750 OC 3.5 ghz, Noctura heatsink, Radeon 5870, Antec 750 PSU, DDR3 1600 mhz.


Posts: 2,050   +14
When you're overclocked, having a cool CPU is pretty hard to acheive.

About changing fan speeds, you can't exactly change it OVER the spec, so if the RPMs correspond with the fan's spec, thats as fast as you can go. Not sure what would happen if you overvoltage it via some other method though, not that I'd know how to wire your PSU to provide more than 12V.

Might want to re-seat your heatsink, that might help. Make sure to use thermalpaste.


Posts: 6   +0
  • Thread Starter Thread Starter
  • #4
CPU temps fixed -- fans were in wrong direction

Thanks to the both of you. I found the issue, and talk about an embarrassing mistake: I had the heatsink fans facing the wrong direction !!! So I turned them around and now my idle is a consistent mid 30s (as opposed to high 30s to mid 40s). I ran Prime95 for just half an hour, and even though it's a very short time, at full load the temp got to mid 50s and stayed there.

Now I have a different and new problem, so I will post a new thread :)


Posts: 8   +0
Just try keeping your temperatures as low as you can. I have a cooling pad with 3 fans that cools my laptop down by USB. These work great, check them out on E-bay. If you are using a tower computer, just remove the casing and throw a big fan on to cool the parts :D


Posts: 3,379   +53
Your temps dont seem out of the norm at all for the oc you achieved. 60C is considered cool for any of the i5-i7 cpus with any fan cooler that's available now. And that's at stock speed, if you're not getting far above that you should be happy.
Not open for further replies.