Arctic Cooling PWM fan - rpm monitoring?

merlin · Post by **merlin** » Tue Feb 10, 2009 10:45 pm

Hey guys,

I picked up a few arctic cooling pwm fans (AF12025's) and they're just as I hoped except I can't seem to detect rpms on it for my Gigabyte EP-35. I have the 4-pin plugged into the cpu fan header, and I didn't expect to need the 3-pin as well. This doesn't seem to make sense as generally most fans work fine with just the 4-pin including rpm monitoring. Am I missing something or could it be that the fan is just spinning too slowly?

Addendum:
Well looks like inspecting the fan wires made it pretty clear how it was setup. I think the instructions paper is definitely wrong about how the system works.(Or perhaps the plug setup has changed for the model I got) Basically the fan is designed to have a cpu fan plug into the 4-pin slot and have the rpm monitor from the cpu fan go through to the mobo. The other 3-pin must be used in another fan header for rpm monitoring on the case fan.
The way to have the fan work alone on one header is simple. Plug the 4 pin in as usual. Plug the 3-pin rpm into the 4-pin slot. Hope that'll be useful info for someone else too

Looks like she's spinning at about 530-600 rpm currently, a nice perfect speed!

jessekopelman · Post by **jessekopelman** » Wed Feb 11, 2009 1:06 am

When you say monitoring isn't working, do you mean it is showing up as 0RPM or as some weird value? If it is showing up as 0, you may have set the PWM percentage and stalled the fan. That is how my AF12025PWM behaves -- shows expected RPM in BIOS and Speedfan when working, shows 0RPM when stalled.

antivenom · Post by **antivenom** » Wed Feb 11, 2009 9:16 am

I have 3 12025's too and for some reason, only having the 4 pin connector in the header doesn't report RPM readings so you either have to plug the yellow cable connector into the 4 pin socket or into another fan header on your motherboard. Don't ask why because I have no idea, just a bad design in my opinion and that's one of the reasons I'm thinking of upgrading to some Noctua's already (I've only had the 12025's for 2 months)

merlin · Post by **merlin** » Wed Feb 11, 2009 1:19 pm

antivenom wrote:I have 3 12025's too and for some reason, only having the 4 pin connector in the header doesn't report RPM readings so you either have to plug the yellow cable connector into the 4 pin socket or into another fan header on your motherboard. Don't ask why because I have no idea, just a bad design in my opinion and that's one of the reasons I'm thinking of upgrading to some Noctua's already (I've only had the 12025's for 2 months)

Hmm, I really like the fans and they were dirt cheap (Can you beat $3.99 + ship/tax for high quality pwm fans?), so this is the only minus. It seems bizarre to need two fan headers to both power and monitor rpm.
And just to note, I doubled checked and the fan is spinning, and fan control software on my mobo does change the fan speed, so it's really just a lack of rpm information without using both fan connectors it seems. Could be an issue with my mobo i guess, but my mobo did detect the rpms on my yate loon non-pwm just fine through the same header.

jessekopelman · Post by **jessekopelman** » Wed Feb 11, 2009 2:22 pm

Well, I have two AF12025PWM daisy-chained from my CPU header and RPM monitoring works fine with just the 4-pin connector . . .

BTW, where'd you get them for $3.99? They usually cost $9.99.

merlin · Post by **merlin** » Wed Feb 11, 2009 3:37 pm

jessekopelman wrote:Well, I have two AF12025PWM daisy-chained from my CPU header and RPM monitoring works fine with just the 4-pin connector . . .

BTW, where'd you get them for $3.99? They usually cost $9.99.

Unfortunately not that cheap now, but ewiz had them for the price. I got 3 and a non-pwm one as well. Right now it's around 5.50 through google shopping I think. Still a decent price.