MSI Z97 MPOWER MAX AC - Fans do not change their speed

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graysky
Posts: 147
Joined: Fri Sep 16, 2005 4:14 pm
Location: My desk

MSI Z97 MPOWER MAX AC - Fans do not change their speed

Post by graysky » Fri Nov 14, 2014 2:32 pm

Just build an i7-4790K system with this board and have my NH-D14 two fans connected to the two CPU fan pins on the MB. I cannot get the smart fan feature in the BIOS to work with either of them; they only run at full throttle despite my adjusting the temp/RPM points. Has anyone with this board or a similar board gotten this feature to work? I should say that I know the fans are capable of running at other speeds because this is the same HSF I used in a different rig where they did work as expected.

Thanks!

Abula
Posts: 3620
Joined: Tue Nov 02, 2004 12:22 pm
Location: Guatemala

Re: MSI Z97 MPOWER MAX AC - Fans do not change their speed

Post by Abula » Fri Nov 14, 2014 3:13 pm

Noctua NH-D14 is an old cooler, that usually comes with 3pin fans, unless its the LGA2011 edition that comes with PWM fans. The MSI motherboard CPU_FAN1 and CPU_FAN2 are true PWM fan headers, and they can only control PWM fans, if a 3pin fan is ran on those headers they will run at full speed (12V), this is the way PWM works, so what you are experiencing is normal.

You have two choices,
1) Replace the stock 3pin fans with PWM fans, like Noctua NF-P14r redux-1500 PWM, with these fans you can use CPU_FAN1 and CPU_FAN2 and control them via bios.
2) Use the SYS_FAN headers, these are voltage controlled headers, so your 3pin fans will be controlled by the bios, with the limitation of 50% as the lowest.

My personal recommendation, is go with PWM, the MSI motherboard will drop those noctua fans to 12.5% kinda like 250rpms or so, you can bump it to 25% or 37.5%, or whatever you like, but you have a huge range to set them up as you prefer.

graysky
Posts: 147
Joined: Fri Sep 16, 2005 4:14 pm
Location: My desk

Re: MSI Z97 MPOWER MAX AC - Fans do not change their speed

Post by graysky » Fri Nov 14, 2014 3:48 pm

Thank you for the reply. My old MB was an Asus P8Z77-V Pro which also had 4-pin connectors on the MB for both of the fans in the D14. Both of these fans are 3-pin as you mentioned. On that MB, I could control them booted into Linux just fine by adjusting the corresponding pwm from the kernel. I tried this on the MSI board without an effect; same for within the BIOS. I know the fans run at variable RPMs with the 3-pin connection. Are you saying that is NOT the case with the newer MSI board and that it must be the 4-pin variety?

Abula
Posts: 3620
Joined: Tue Nov 02, 2004 12:22 pm
Location: Guatemala

Re: MSI Z97 MPOWER MAX AC - Fans do not change their speed

Post by Abula » Fri Nov 14, 2014 3:59 pm

Asus motherboards on their CPU_FAN header, have the option on the bios to switch between 3pin voltage controlled to 4pin PWM, from what i remember was called Q-FAN (switching from AUTO to ADVANCED), but this is not the case with MSI. But specially for you running linux, having the fans ran by bios would be very nice imo, as you wont need anything extra, and you can switch between OS. Personally i like much more how MSI is much more tweakable on BIOS than Asus for pure fan control, but that doesnt mean Asus is bad, its a superb motherboard imo, but it excels much more with FanXpert.

graysky
Posts: 147
Joined: Fri Sep 16, 2005 4:14 pm
Location: My desk

Re: MSI Z97 MPOWER MAX AC - Fans do not change their speed

Post by graysky » Fri Nov 14, 2014 4:42 pm

@Abula - You were right! I studied the manual closely and it seems that the two CPU fan connectors expect the 4 pins to be:
1) Ground
2) +12V
3) Sense
4) Speed control

The three SYS fan connectors expect the 4 pins to be:
1) Ground
2) Speed control
3) Sense
4) NC

I hooked up my two CPU fans to the SYS headers and all is well. Thanks!

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