this post was submitted on 16 Jan 2026
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I disassembled an AMD CPU Wraith Cooler, meaning, I took the fan off of the heatsink, because I want to attach the fan on top of a Raspberry Pi that I'm using as a router. The Pi runs quite hot because it transmits several hundred megabytes per second, non stop, and I want to give it some cooling. (It already has its own heatsinks on its various chips inside the chassi and I don't want to use the little shitty Okdo fan, because it's loud.)

Is there any smart solution to how I could power this 4-pin fan? It needs 12V DC.

This is the Pi with its chassi.

And I'm considering something barbaric like this.

~~Are there perhaps conveniently positioned GPIO pins on the Pi that the 4-pin connector could just slide on to and just work?~~ Never mind this. The Pi 4 that I'm using can only output 5V:

Or would I need to cut off the 4-pin connector to expose the individual wires and attach them to a 12V DC adapter?

Or any other genuis solutions? :)

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[–] Romkslrqusz@lemmy.zip 2 points 1 day ago* (last edited 1 day ago) (1 children)

Assuming the supply can saturate the current the fan will use, at 12V it’ll be running at full speed. That’s probably pretty loud. Give it 5V, it’ll run slower and quieter.

[–] emotional_soup_88@programming.dev 1 points 1 day ago (1 children)

I just found a "noise reduction cable" from Noctua. It ads 51 Ohms. I have no idea how to calculate what the new voltage would be on a 12V 2A DC power supply ( https://www.noctua.at/en/products/nv-ps1/specifications ), but Noctua's website says that the cable lowers fan speeds, so I'll give it a try.

[–] Romkslrqusz@lemmy.zip 3 points 22 hours ago

Yeah, it’s just an inline resistor

A potentiometer is a resistor that you adjust using a dial. If you want control, you may want to get a PWM fan control module. There’s the Noctua NA-FC1 https://www.noctua.at/en/products/na-fc1 but that’s pretty much just a fancy expensive version, you can find the same concept for as little as $1-2 USD