Sign in with
Sign up | Sign in
Your question

Change fan rpm in bios

Tags:
  • BIOS
  • Fan
  • Systems
  • Be Quiet!
Last response: in Systems
Share
March 27, 2014 11:48:45 PM

Hello , I just bought 2 be quiet! Shadow Wings PWM fans , 1 with 80mm and 1 with 92mm , but they are pretty loud , and I think because they are running on full rpm , how can I make the rpm lower in the bios and which rpm is normal for case fans? PS: They are connected with a 3 pin Y cable on 1 header with 3 pins!

More about : change fan rpm bios

March 27, 2014 11:56:17 PM

Are they plugged into 4pin pwm fan headers on the MOBO?
m
0
l
March 27, 2014 11:59:42 PM

Use your UEFI if you got it
m
0
l
Related resources
March 28, 2014 12:01:47 AM

If they only have three pins, they don't have the necessary PWM control line to allow speed control.

On both 3 and 4 pin fans, one of the wires is used for speed sensing. So even 2 pin fans can be compared.
2 pins: Voltage and ground (the same as many other electrical devices)
3 pins: Voltage, ground, and RPM sensing
4 pins: Voltage, ground, RPM sensing, and PWM control
m
0
l
March 28, 2014 12:03:26 AM

To change the speed in BIOS they have to be powered from the mb and not from a molex .
How you do that varies with the BIOS so just go have a look for fan speeds . On modern boards they wont have to be pwm fans and/or in foour pin headers . The BIOS can change voltage to a 3 pin and slow the fan .


If you have them plugged in to a molex directly to the power supply you can modify the voltage by following these instructions
http://www.techpowerup.com/articles/other/137
m
0
l
March 28, 2014 12:07:34 AM

logang said:
Are they plugged into 4pin pwm fan headers on the MOBO?


They are both 4 pin but connected on 1 mobo sys_fan header which has 3 pins
m
0
l
March 28, 2014 12:53:28 AM

On my MSI motherboard you can set min temp and min fan speed and then max temp and max fan speed in the bios.
You have to tick the smart fan box and from then on the mobo controls the fans depending on case/CPU temps.
This way the PC is nice and quite when just doing browsing and low load stuff.
My fans are 3 pin plugged into 4 pin headers.
I did have to buy some extension cables to reach all the fan headers.
m
0
l
March 28, 2014 1:59:55 AM

On my ASRock mobo I set fan speed and temp. (temp just changes the fan profile so the fan rpm increase or decrease for a certain temp). This is done using the ASRock UEFI. I think some fans are pwm and some are just voltage controlled. The advantage of pwm is that there is less power wasted as heat.
m
0
l
!