3pin to 4 pin fan splitter. How to check if it works

Toggle sidebar Toggle sidebar
TwistinFool

TwistinFool

Reputable
Feb 17, 2015
22
0
4,510
My motherboard has 4 pin fan headers and my fans have 3pin. I understand the 4th pin is PWN and allows the motherboard to adjust its RPM accordingly to cool the computer when it gets warm.

I also watched a video where they spoke of a fan splitter. I wanted to try this out so I purchased this item.

Two questions, if say I have a 3 pin fan AND a 4 pin fan, then could I plug both of those in on the male ends and put the female end into the motherboard? Or can I only use one fan per splitter?

Second, and ultimately, how can I check if my motherboard is controlling the fan accordingly to temperature changes? Any software? I haven't built my computer yet, but the motherboard I have is the asus maximus 7 hero. Will I be able to monitor the chassis fans with AI Suite software and can I basically confirm my question by monitoring if the fans do change on its own? Because if I understand it correctly, 3pin will run at 100% and if I do this 4 pin splitter, then there should be fluctuations in the power and rpms.

Thanks for taking the time read and help,


 
Solution
H
Your motherboard can control fan speed for both 4-pin fans and 3-pin fans based on temperature. It has a super-sophisticated fan controller built in with Fan Xpert software.

While you can connect either 3-pin or 4-pin fans to 4-pin headers (with or without splitters), you won't want to do so because it will make it much more difficult (if not impossible) to use the motherboard's fan control -- any given header can either be configured to control 4-pin PWM fans or voltage controlled 3-pin fans. It can't do both at the same time. The fans will work, but speed control may not work properly. It would have to treat the 4-pin fans as 3-pin voltage controlled fans.

So you want to use some fan headers on your MB exclusively for 4-pin PWM fans...
Sort by date Sort by votes
geofelt

geofelt

Titan
Oct 9, 2006
54,262
4,125
174,240
Any fan needs only two pins to run at full speed.
In a three pin fan, the third pin is a speed sensor.
The speed sensor lead allows the motherboard to control the fan speed by adjusting the fan voltage down from it's nominal 12 volts.
In a 4 pin fan, the speed is managed by pulse width modulation.
The motherboard sends voltage pulsed to the fan. The longer the interval between pulses, the slower the fan runs.
Some modern motherboards can detect which type of fan you plugged into the motherboard header and act accordingly.
Splitters will omit the speed sensor lead on the second fan to keep from confusing the motherboard.
Both fans will be controlled the same. Splitters are good for cpu coolers that include two fans.

A modern motherboard will have fan profiles that can be set in the bios.
You can also manage fans with a free app like speedfan.

Personally, I dislike varying fan speeds. I set mine at a constant speed that cools well enough and yet is not too noisy.
 
Upvote 0 Downvote
H

hwc1954

Reputable
Jan 7, 2015
318
2
4,860
Your motherboard can control fan speed for both 4-pin fans and 3-pin fans based on temperature. It has a super-sophisticated fan controller built in with Fan Xpert software.

While you can connect either 3-pin or 4-pin fans to 4-pin headers (with or without splitters), you won't want to do so because it will make it much more difficult (if not impossible) to use the motherboard's fan control -- any given header can either be configured to control 4-pin PWM fans or voltage controlled 3-pin fans. It can't do both at the same time. The fans will work, but speed control may not work properly. It would have to treat the 4-pin fans as 3-pin voltage controlled fans.

So you want to use some fan headers on your MB exclusively for 4-pin PWM fans and some exclusively for 3-pin voltage controlled fans. The MB can handle both just fine. It just can handle them both connected to the same fan header at the same time with a splitter.

 
Upvote 0 Downvote
Solution
TwistinFool

TwistinFool

Reputable
Feb 17, 2015
22
0
4,510

So essentially,
Example1 = GOOD
Chassis Fan 1 (4pin) - Using two identical 3 pin fans via splitter

Example2 = Bad
Chassis Fan 1 (4pin) - Using one 3 pin and one 4 pin fan via splitter

Am I understanding this correctly? Using a splitter, a fan header should have two 3 pin or two 4 pin, not one of each in one header?

And if I'm doing the 3 pin scheme, all the chassis fan headers should be the 3 pin as well?


 
Upvote 0 Downvote
H

hwc1954

Reputable
Jan 7, 2015
318
2
4,860


Correct. For an one fan header, all 3-pin or all 4-pin fans. Not both, if you want to be able to speed control them.



That depends on the motherboard and its fan control options. If it has settings for each individual chassis_fan header, then you would mix and match -- PWM fans on some headers, voltage control on another. If the MB has one setting for all chassis fan headers, then you might have problems.

It's not the end of the world. 4-pin fans can be used like 3-pin fans with voltage control. It's just a potential complication.

 
Upvote 0 Downvote
You must log in or register to reply here.

TRENDING THREADS

Latest posts

Moderators online

Share this page

COMPANY
RESOURCES
FOLLOW
Top Bottom