CPU Fan Not Spinning Up

Ph4lanx · 23 May 2010 at 01:59

Hi guys,

OK so I've been happily using my Noctua NH-D14 for about a week now, no problems.

However, I decided to just test to see the fans were working correctly, and came across this problem.

As you can see, I'm running Prime95 at full whack on each thread, all four cores are sitting on around 57 degrees at full load, and SpeedFan is reporting a RPM on the CPU fan of 1,200 odd RPM. This is the idle speed, which leads me to believe that the Noctua 140mm and 120mm are not being controlled correctly by the motherboard.

The pin connector I used for the two fans is one that combines them into a single pin, which I was then told to plug into the 4-pin PWM header on the motherboard, even though it is a 3-pin cable.

I'm wondering if I've set this up wrong on my motherboard or have I missed something?

iNPUt · 23 May 2010 at 02:19

I think its done by heat not load, so its fine..

Ph4lanx · 23 May 2010 at 03:07

Really? I'm just really nervous now to overclock, incase the CPU fan doesn't kick in and screws something over

RJC · 23 May 2010 at 09:22

Check your BIOS options, it may of set up the fan for quiet operation.
The fan's usually increase with temperature, with your cpu being at 55c your well within limits, I prefer to keep under 75c full load.

Ph4lanx · 23 May 2010 at 11:00

Well I've even tried to spin up the fan using SpeedFan but nothing seems to respond. I'm not sure if I misunderstand how SpeedFan works, but it seems I can't spin up any of the fans that it shows.

I'm wondering if, because it's a 3pin, it's simply not controllable and is running at full RPM all the time.

Is there something I can do to make it so the fan is controllable? Perhaps some sort of cable converter?

I did have a look for 3pin to 4pin adapters, but it seems every 4pin adapter I find is to a molex connection instead of a 4pin PWM.

Ph4lanx · 23 May 2010 at 12:12

Would this solve the problem?

http://www.overclockers.co.uk/showproduct.php?prodid=CB-031-AK&utm_source=froogle

Akempster · 23 May 2010 at 22:49

i agree with ph4lanx about the 3 pin cable . Without the 4th pin theres no way for it to be controlled. It will just run at full whack. You could wire their PWM cable inline then this to the mobo whilst attatching one fans power to a molex connector instead of the mobo to get full power out of both whilst still being controllable. Although, thats likely to make it give yu double the power for what it thinks the cmputer needs.