[SOLVED] Old CPU fan on a newer motherboard as a system fan

[Kokodaka]

Hi! I found this really old 3-pin CPU fan on one of my old PCs (12 years old). I was wondering if I could use it as an additional system fan on my 2016 build.

Motherboard: MSI Z170-A PRO (MS-7971).

The old fan: DC12V 0.24A

I really don't want to fry anything and that's why I am asking this.

Thanks!

 

[COLGeek]

Yes. Just expect it to run fast (loud) and not move a lot of air. Otherwise, it should work.

 

[Karadjgne]

Most motherboards (now) have 3 different settings for fan headers.

1. PWM. This is a constant 12v supply where the pulse switches the fan on/off to control speeds.
2. DC. This is where voltages are variable between 5v and 12v to control fan speeds.
3. Auto. This allows the motherboard to sense what is plugged into the header, either 3pin DC or 4pin PWM, and respond accordingly to allow control.

So for that fan, to have speed control, either all headers must be on DC or auto, or if individual headers, that one the fan is plugged into must be DC or auto.

If all headers are PWM, then that fan will get a constant 12v and spin at max 100%, all of the time.

All fans have an MTBF. That's Mean Time Before Fail. Most decent fans will have at least a 50,000hr MTBF. That's roughly 5.7 years of constant usage. So depending on exactly how long that fan saw operation, at 12 years old already and use on a cpu cooler, you may get a day out of it or a week or a year, but you could expect it's going to reach failure point in the foreseeable future, seriously doubt it will last long unless it's a Noctua fan or similar which have MTBF of 150,000 hrs or constant usage for 16+ years.