3 fans off of one SYS_FAN Header? Is it possible?

[lofemofe]

The CPU header on my MOBO seems to have broken. I thought it was the cooler, replaced the cooler and still doesn't work. So I'm running my CPU fan right now off of a SYS_FAN header in PWM mode and controlling the fan profile with Gigabyte software.

My temps on my GPU are reaching max and throttling now though. It's not too bad for gaming but when trying to OC I can't get consistent results obviously because of the throttling.

So I want to get my rear fan going again and add a front intake fan as well. I want them all to run in PWM mode so that I can ensure my CPU is being cooled correctly. Is it possible to get a 3 way splitter that is PWM and run 3 fans off of one SYS_FAN header? And once I do with all 3 be controllable RPM?

 

[alexoiu]

I'd rather go with a fan controller, PWM capable
http://www.newegg.com/Product/ProductList.aspx?Submit=ENE&DEPA=0&Order=BESTMATCH&Description=fan+controller+pwm&N=-1&isNodeId=1

 

[photonboy]

1) Yes, you can get 4-pin fan splitters.

I'll POST this now then look for a link.

2) The total MAX amperage must not exceed the fan header rating (see motherboard). For example, if the fan header was 1A max (I forget) and max for each fan was 400mA then you can only support two fans.

3) Ideally all fans should be identical or at least close in their range (i.e. 500RPM to 1800RPM), 4-pin. If different the duty cycle should mean the fan with the highest RPM spins faster (proportionately).

4) *I would advise running the FRONT fan separately. Even a non-variable, quality fan of no more than 1000RPM is probably sufficient. That doesn't even need a fan header.

5) I'm buying two Noctua case fans (a bit expensive) now that my current ones are failing. They are non-variable because even though my current ones ARE variable they simply make little difference to my cooling. They never exceed 800RPM based on my temperature profile though your needs may differ.

I'm getting the NF-S12A ULN fans which run a constant 800RPM.

(800RPM is not a direct indicator of cooling potential. There are different designs optimized for different tasks.) You can find more info at Noctua even if you do not buy there.
http://noctua.at/en/which_fan_is_right_for_me

6) **SIDE FAN is most important for GPU cooling, though your case may not support it. In general, the closer the fan to the chip being cooled the better.

 

[photonboy]

Example 3x, PWM splitter:
https://www.amazon.com/Phobya-3-Way-Splitter-Single-Connection/dp/B004CLFOK4/ref=sr_1_17?s=electronics&ie=UTF8&qid=1472363224&sr=1-17&keywords=fan+splitter

 

[photonboy]

I'd rather go with a fan controller, PWM capable
http://www.newegg.com/Product/ProductList.aspx?Submit=ENE&DEPA=0&Order=BESTMATCH&Description=fan+controller+pwm&N=-1&isNodeId=1

I would NOT do this when he can use his motherboard and fan control software to accomplish the same thing for less money.

 

[alexoiu]

I'd rather go with a fan controller, PWM capable
http://www.newegg.com/Product/ProductList.aspx?Submit=ENE&DEPA=0&Order=BESTMATCH&Description=fan+controller+pwm&N=-1&isNodeId=1

I would NOT do this when he can use his motherboard and fan control software to accomplish the same thing for less money.

ok

 

[lofemofe]

1) Yes, you can get 4-pin fan splitters.

I'll POST this now then look for a link.

2) The total MAX amperage must not exceed the fan header rating (see motherboard). For example, if the fan header was 1A max (I forget) and max for each fan was 400mA then you can only support two fans.

3) Ideally all fans should be identical or at least close in their range (i.e. 500RPM to 1800RPM), 4-pin. If different the duty cycle should mean the fan with the highest RPM spins faster (proportionately).

4) *I would advise running the FRONT fan separately. Even a non-variable, quality fan of no more than 1000RPM is probably sufficient. That doesn't even need a fan header.

5) I'm buying two Noctua case fans (a bit expensive) now that my current ones are failing. They are non-variable because even though my current ones ARE variable they simply make little difference to my cooling. They never exceed 800RPM based on my temperature profile though your needs may differ.

I'm getting the NF-S12A ULN fans which run a constant 800RPM.

(800RPM is not a direct indicator of cooling potential. There are different designs optimized for different tasks.) You can find more info at Noctua even if you do not buy there.
http://noctua.at/en/which_fan_is_right_for_me

6) **SIDE FAN is most important for GPU cooling, though your case may not support it. In general, the closer the fan to the chip being cooled the better.

Thank you for an well informed and detailed post. I've been asking questions all month due to my new rig and this is one of the best responses I have gotten. I will check the Amperages of my Sys Fan header tomorrow and see if it works out!