VOID

Triple B

n/a

Foomy

Grab your motherboard manual, it will label all the fan headers.

And by small fan that came with your mobo i assume you mean one that goes on the southbridge? Your usualy only suposed to use those if your using water cooling.

And the smaller or faster a fan is the noiser it will be.

Donovan Puppyfucker

Actually you can put the mobo fans in regardless of whether you use an air cooler or water cooler - they're supposed to pump air under the mobo cover to cool the mosfets and chokes.

AUXFANIN1 is obviously AUXiliary INput FAN #1. So yeah, it's one of the weeny mobo fans. I can't remember off the top of my head if it's the one at the top left or around the middle of the board, depending on which it is, you may be able to replace it with a 40mm fan that runs a smidge quieter.

As far as I remember, the stock 35mm fans can rev all the way up to 6400rpm maximum.

Triple B

So, no reason to panic then? I'm still kind of gun shy since my last rig died less than 2 years after I bought it. >.> I just thought it was weird that I've had this thing since mid August and it's never revved like that before. It was literally just quick 1-second bursts, like someone revving an engine.

Donovan Puppyfucker

I'm pretty sure it's just a munted fan.

GnomeTank

You could just pop the side off your case and look. Are all the fans spinning? You're good. If you visibly see one stuttering or struggling, it's probably time to replace that fan. It's also much easier to locate the source of the noise if you stick your head near it.