post #1 of 1
Thread Starter 
Hello all,

I’ve got a very specific situation and I’m hoping one or more of you fine people can assist me in finding a solution. Maybe it can even help others. It’s pretty straightforward but I don’t have the knowledge to get the job done.

First, some backstory might be useful. I’ve got three Sapphire HD 7970s and one Gigabyte HD 7970. I want to implement a four-way CrossFire setup but of course the Sapphire cards are wider than two slots. I’ve been able to acquire Gigabyte HSFs and will replace the Sapphire HSFs with those so I can utilize all four cards in CrossFire. An LCS is not an option because it’s too freakin’ expensive.

Now, my issue: The Sapphire HSFs’ fans are PWM controlled. The Gigabyte fans use a three-pin connector. What sort of setup should I use to allow the control voltages from the Gigabyte card (which of course will be the master connected to the display(s)) to also control the fans of the other three cards, and provide sufficient power to drive all the GPU fans (a total of 12)? I want them to ramp up and down as required, not be at full blast all the time – that’d be easy, but excessive, inelegant, noisy, and inefficient – not to mention a great way to dump unnecessary ambient dust into the system and shorten the fans’ lifetimes.

Thanks in advance for your help in this.
Edited by wsh777 - 8/28/13 at 8:32am