PWM fan running at constant full speed

[Agenz]

I'm having an issue with the PWM fans that I've recently installed, they appear to be running at full speed despite being connected to a 4 pin fan header.

 

I'm using three Noctua NF-P14r redux-1500 PWM fans connected to sysfan1 on my Z97 PC mate motherboard using an Akasa AK-CBFA07-45 Flexa FP5S PWM Splitter Cable.

 

After looking at the manual for my motherboard and quick internet search it appears that the pin out for sysfan1 is different to that needed for pwm control, is this the case?.

 

If so it looks like cpufan2 has the correct pinout, could I plug the fans into this header? Or do I need a different solution?

 

Thanks, let me know if I need to provide any more information.

 

Just looked at the MSI command centre, it says the fans are at full speed despite being on the 50% setting

[Trik'Stari]

You ought to be able to control the 4 pin fans via the bios on your motherboard, can you not?

[Agenz]

I've had a look but nothing seems to change when I use the different settings in the hardware monitor

 

Is the pinout 1. Ground, 2. Speed Control, 3. Sense and 4.NC correct for PWM fans?

[MLGNOSCOPEHEADSHOTGETREKT]

You should be able to change it since it's PWM...Just look in UEFI

[Agenz]

Where should I be looking exactly?

[Agenz]

Is it ok to plug it into the cpufan header to see if the fans run at a different speed?

[Agenz]

Just tried the fans off the cpu header and they ran alot quieter, nots sure if its ok to keep it that way though.

[blackadder]

Just tried the fans off the cpu header and they ran alot quieter, nots sure if its ok to keep it that way though.

if temps are good it should be.

[Agenz]

if temps are good it should be.

How would I best determine if the temps are "good" while controllig them off the cpu header?

[blackadder]

How would I best determine if the temps are "good" while controllig them off the cpu header?

what are cpu temps, when your pc is stressed. Cpu temp should be under 90c (we always like lower 80c) gpu temp depends more on type of gpu.

[Agenz]

what are cpu temps, when your pc is stressed. Cpu temp should be under 90c (we always like lower 80c) gpu temp depends more on type of gpu.

Thanks for the replies, I guess I'll wait until I next use the computer for an extended period of time gaming and see what the cpu temp reads afterwards, if it's within those limits I'll stick with what I've got.

 

As for gpu I have a Gigabyte Nvidia Gtx 960 Windforce 2 OC PCI-E Graphics Card,  any ideas what temps I can safely use that with?

[blackadder]

Thanks for the replies, I guess I'll wait until I next use the computer for an extended period of time gaming and see what the cpu temp reads afterwards, if it's within those limits I'll stick with what I've got.

As for gpu I have a Gigabyte Nvidia Gtx 960 Windforce 2 OC PCI-E Graphics Card, any ideas what temps I can safely use that with?

i would take my give unless you live in lava it will never get above 75c

[dfsdfgfkjsefoiqzemnd]

The problem is the motherboard fan header.  Despite being 4-pin, on many MSI boards it's not PWM but actually uses voltage to control the fan RPM. 

I had the exact same problem when I tried the exact same thing with the exact same splitter on my MSI Z77A-GD65 Gaming. 

 

The motherboard doesn't send out a PWM signal but does send out a voltage.  However because the splitter gets only the PWM off the header and the voltage from the Molex plug, it actually ends up getting no signal from the motherboard at all.  .  It does get 12V from the Molex plug though, so the fans are going at full speed all the time.

 

Find out the headers' maximum output (contact MSI if necessary).  On my board it turned out to be just enough to run all my case fans with regular Y-splitters, so I ended up doing that. (running 5x SilentWings2 on a single header, fans are 0.2A each and MSI support told me my board is rated for 1A per header.  So my PWM fans are now using voltage control)

 

There is ONE header on the motherboard that does have proper PWM, and that's the CPU header.  So if you don't mind coupling the case fan speed to the CPU fan speed, that would be an option.  You could plug the splitter in the CPU header and connect the CPU cooler to the one cable that has the sensor pin.

That will allow you to set up a profile for the CPU cooler in Speedfan, and the case fans wil spin up and down together with the CPU cooler.