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Cpu fan on gene-z

spriggan
Level 7
Hi! I've recently came close to finishing my first build, but a slight problem occured. My cpu cooler fan has 3 pin connector (thermalright axp-140), but my gene-z mobo as you know has 4 pin slots for fans. So I have a question, will fans work if I connect them to 4 pin slot? What problems there may be? If they'll work I'll probably wont be able to monitor and/or change fan speed or something like that? Thanks in advance.
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4 REPLIES 4

harly
Level 7
As I understand it, the two CPU headers only control 4-pin fans. 3-pin fans will run at max speed. The 3 Chassis headers will control 3 or 4 pin fans though.

I also read that in a recent bios change that one of the chassis controllers (fan 3 maybe?) goes off the CPU temp not the mobo temp, a change made for your very circumstance. Someone posted that in these forums. I haven't confirmed if it is true though, so take that with a huge grain of salt unless you can confirm it somewhere authoritative.

HiVizMan
Level 40
Thanks for that tit bit harly

if I get a chance today I will put my Gene on the test bench.
To help us help you - please provide as much information about your system and the problem as possible.

Thanks! That bios option would be great, it would be nice if someone could confirm it or even better, teach how it's done:)

puma99dk_
Level 9
the forth wire is usually used for PWM fans (Pulse-width modulation.)

i use two Noctua NF-P12 with 3pin connectors on my Noctua NH-U12P SE1366 and i have never had a problem not even on my Gene-Z/Gen3 i use both CPU and OPT fan connector.

Pulse-width modulation

Pulse-width modulation (PWM) is a common method of controlling computer fans. A PWM capable fan is usually connected to a 4-pin connector (pinout: Ground, +12V, sense, control). The sense pin is used to measure the rotation speed of the fan and the control pin is a open-drain or open-collector output, which requires a pull-up to 5V or 3.3V in the fan. Unlike linear voltage regulation, where the fan voltage is proportional to the speed, the fan is driven with a constant supply voltage; the speed control is performed by the fan based on the control signal.

The control signal is a square wave operating at 25kHz, with the duty cycle determining the fan speed. Typically a fan can be driven between about 30% and 100% of the rated fan speed, using a signal with up to 100% duty cycle. The exact speed behaviour (linear, off until a threshold value, or a minimum speed until a threshold) at low control levels is manufacturer-dependent.


http://en.wikipedia.org/wiki/Fan_control