• Now's your chance win big! Join our community and get entered to win a RTX 2060 GPU, plus more! Join here.

    Pi Cast Episode 3 streams live on Tuesday, August 4th at 2:30 pm ET (7:30 PM BST). Watch live right here!

    Catch Scharon on the Tom's Hardware Show live on Thursday, August 6th at 2:00 pm ET (7:00 PM BST). Click here!

Question Need some Fan Help!

Jul 7, 2020
17
0
10
0
Hey guys I’m a little bit lost with the fan situation in my PC. I have 1 exhaust fan and 1 intake fan. So I decided to add a splitter so I can have 1 more exhaust fan but the issue is one fan is 4 pin and the other fan is 3 pin. Do I leave it on pwm or dc in the bios settings. Or should I not even use the splitter and just leave the 2 fan setup.
 

Zerk2012

Polypheme
Ambassador
I would probably add another front intake instead. If you using a 4 pin splitter it really don't matter because if you really look at it only one plug for the fan should actually be 4 pin (wires) the other should be 3.
 
Jul 7, 2020
17
0
10
0
I would probably add another front intake instead. If you using a 4 pin splitter it really don't matter because if you really look at it only one plug for the fan should actually be 4 pin (wires) the other should be 3.
So I should have 1 exhaust fan in the back and 2 intake fans in the front?
 

Phaaze88

Splendid
Ambassador
Well, PWM doesn't affect the 3pin fan anyway - by that, I mean, you can't control it in the same manner as PWM.
You'll need to change the header to DC mode. There's a limit to how low a DC fan will run; if you try to set the 3pin to run at 30%, the command will either be reset or ignored, running at 100% anyway.
Depends on the fan model, but the lowest a DC fan can go is somewhere around 40-60%.
 

Zerk2012

Polypheme
Ambassador
Well, PWM doesn't affect the 3pin fan anyway - by that, I mean, you can't control it in the same manner as PWM.
You'll need to change the header to DC mode. There's a limit to how low a DC fan will run; if you try to set the 3pin to run at 30%, the command will either be reset or ignored, running at 100% anyway.
Depends on the fan model, but the lowest a DC fan can go is somewhere around 40-60%.
using a splitter cable their should only be one 4 pin ( pins don't really matter but just one 4 wire plug) for the fans to plug into the others should be 3 or even 2 pin so the motherboard does not get mixed signals on the RPM that would make the motherboard raise or lower voltage that would also affect the 3 pin fan.

The 4 pin fan should be plugged into the 4 pin splitter and the 3 pin fan plugged into the other tht would control the speed of both fans.
 
Last edited:

Zerk2012

Polypheme
Ambassador
Jul 7, 2020
17
0
10
0
Example 4 pin splitter cable.

https://www.newegg.com/p/N82E16812162026?Description=fan splitter&cm_re=fan_splitter--12-162-026--Product&quicklink=true

Note the Picture here only one fan actually has 4 pins (wires) that is what the motherboard would read but still changes the voltage to both fans depending on temp. 4 pin fan plugged into the 4 pin slot and the 3 pin fan plugged into the other.

https://c1.neweggimages.com/NeweggImage/ProductImageCompressAll1280/12-162-026-02.jpg
Yes exactly although the 4 pin fan runs on low Rpms while the 3 pin fan is running at 100% why is that ?
 

ASK THE COMMUNITY

TRENDING THREADS