Looking for a good fan controller

RazzRaccoon · August 6, 2021

First post to LTT fourms woohoo!

Hello all. I currently have server on a rack that is 4U in size. I've been looking around for a Fan controller that will fit my needs well but im not finding anything so I'm curious if anyone else knew of anything that maybe I'm missing. I have 3 fans and they can pull 2A at the most. They also use PWM.

I've already gone through two amazon controllers (both non PWM) but the mosfets on them just cant handle it if I need everything on high speed. I have tried plugging them into the motherboard but they run too fast for the slowest speed so thats out.
Was considering an industrial controller but I'm not that desperate yet.

The controller Im looking for would be ideally:

Under $100

Able to handle pulling a max of 7A @ 12V (most important)
Fits in a 5.25 bay (can 3D print something to adapt if needed)
Able to adjust according to set conditions (external or internal)

Bombastinator · August 6, 2021

With only 3 fans if you’re not dealing with RGB you can just plug them into the motherboard. Even if there’s only one motherboard fan headers a 3 way “y” splitter will do you if they’re all going to run at the same speed and are the same size. If it’s an rgb issue there are specific rgb only controllers but that gets into proprietary connector crap I don’t bother to understand myself. If rgb is a thing though you’re going to have to deal with fan make and model (because it’s not always even between makes) and since none is listed there’s no way to make a recommendation. Fan pwm is fan pwm though and unless the motherboard is really old it will have pwm motherboard headers. Probably more than one. Fan speed is totally controllable via pwm from motherboard fan curves. Could be your motherboard is broken I guess.

Edited August 6, 2021 by Bombastinator

Jarsky · August 6, 2021

51 minutes ago, RazzRaccoon said:

I have tried plugging them into the motherboard but they run too fast for the slowest speed so thats out.

This has me a little confused, if your board is running in PWM mode then they should be able to run fairly slow in a "Quiet" fan curve on most motherboards.

You sure they aren't in DC mode? Also if you dont need the max speed, you could put an inline resistor in, which many such as those from Noctua (their Low Noise Adapters) drop approx 500rpm, they are suitable up to 2.5A fans to cover their industrial (PPA range) fans

RazzRaccoon · August 6, 2021

I'll double check the setting in the UEFI but the from what I remember the slowest I was able to run something was 50% Duty cycle manually. Automatic setting just ran them about the same. (this board does not have an RPM graph or anything) I did see the Noctua fan controller there I'll have to consider that as well if it can handle the amperage.