Wiring case fans to a GPU

sushmee · October 2, 2018

So, hello.

Kinda new here, but here we go. I'm maintaining a mining farm for a company and I'm having issues with fans. More and more fans are starting do die on me so I have to replace them.

Currently, I got these case fans: Image

I'm replacing these GPU stock fans: Image Image 2

I was hoping I'll be able to patch them up, wire them and plug them directly onto GPU. But I've noticed case fans have 2 pins and the GPU stock fans have 4

Is it possible to do that and could someone explain me how to? Thanks!

emosun · October 2, 2018

if you don't care about looks or jimmy rigging things.......

then one thing you can do is leave the old gpu fans plugged in but simply remove the rotors from them

then install/wire the new case fans right to the power supply.

this will make the gpu think it's original fans are still plugged in. If you try to unplug the old fans from the gpu without using proper replacements the gpu with pitch a fit over it.

mariushm · October 2, 2018

The pinout is standardized (from left side of connector to right side) : ground, voltage (+12v) , rpm (fan sends signal to card which tells card how fast fan spins) , pwm (card sends signal to fan to adjust speed)

The rpm and pwm wires can miss, they're optional. if the rpm wire is missing, card and software can't measure fan speed. Some cards may complain about fan being dead and may throttle themselves down. Unlikely.

If the pwm wire is not connected, fan will always run at 100% speed.

You can buy loads of fans of various sizes from here, with or without connectors, with 2,3 or 4 wires (all will work on video cards) : link

You can also find those fans on eBay or aliExpress, just search for that code pld09210s12hh ....

Anyway, try not to go overboard on current, don't buy fans that need more than around 0.5A or you may burn the fan headers on the video card.

Hackentosher · October 2, 2018

It may be beneficial to replace those deepcool fans with some high performance deltas and let the gpu fans run on their own. If you're mining, the gpus will be 100% all the time anyway, so I don't see any point in having the gpu contre fans if they're just going to be full blast, that just sounds like more hassal than it's worth to me.

sushmee · October 3, 2018

I left it over the night, those two DeepCool fans attached and turned on. I plugged them with Molex connectors, didn't wanna wire anything until I see answers from here. Seems like the card overheated over the night, so those fans aren't able to cool the GPU down.

What do you think about these? Link

Will those fan be able to do the job? I see it's approximately the same size as the original ones

If I order those fans, can I wire two of them them onto this and plug it directly to gpu? Image

rentaspoon · October 4, 2018

On 10/3/2018 at 11:39 AM, sushmee said:

If I order those fans, can I wire two of them them onto this and plug it directly to gpu? Image

It's suggested not to as your GPU might not be able to handle the wattage best to throw an email to the maker of the gpu card.

In theory you should be able to take the 12v+ and ground from a molex plug and then wire the tacho and pwm wire to the GPU without issues but I haven't tested this out yet so it's a use at your own risk idea or look use the pwm standards and see if it's possible.