In short: Is it possible to control the speed of a fan that is plugged in one of the mainboard fan inputs based on the GPU temperature reading? In long: Currently I have an unusual video card issue with a GTX 590 card. A small chip on it is blown and it causes 1 of the 2 GPUs not to work at all. The other one works, but there it has no control of the fan speed which is locked at 40%. Purchasing a custom GTX 590 cooler will cost more than the current value of the card, so what I want to do is connect the wires of the GPU fan to one of the mainboard fan inputs and find some software to control the fan speed based on the GPU temperature. Is this possible to happen?
I don't think you'll be able to find software that will do what you are trying to do. You'd be better off buying a cheap fan controller and plugging it into that.
Worse case scenario is that I use a manual fan control with a front panel add-on. Problem is if someone else comes to use it while I'm away.
Nice one. I'll look into it when I get home. In the meantime I did some measurings yesterday. The GPU fan has 4 wires and the voltage readings were as follows (pin order might be the other way around): pin 1 --> 0.99 V pin 2 --> 1.65 V pin 3 --> 12.0 V pin 4 --> 0.00 V These voltages are no longer software controlled (normally the BIOS of the bad GPU controls them). I couldn't understand how I manually mod these, so I checked the same values on the working GTX 580 and I got the following: pin 1 --> Up to 3.30 V (when I set fan to 100% it reads 3.3V. Voltage decreases as the fan speed goes down) pin 2 --> 1.65 V pin 3 --> 12.0 V pin 4 --> 0.00 V Since the onboard fans are 100% at 12V, I need another mod to make 100% at 3.3V. Another resistance maybe. Boy, this is more complicated that I expected.
The fan used is PWM type (4pin) so you have ground, 12v, sense and control wires . http://en.wikipedia.org/wiki/Computer_fan_control#PWM-FAN PWM uses duty cycle pulses of voltage not variable voltage to fan (7-12v) .
??? WTF? :bang: So if I manually control that voltage it will have no affect? I still plan to try and find out. Perhaps it works eitherway. The voltage of that pin scales up to 3.3V on a healthy GTX580 card. And I don't plan to throw money into this one now.
try it, I am just stating what PWM signal is needed , which I believe is being used . On newer MB they support both types of fans ,at least popular ones do . Same with fan controllers many support both there too .