CPU Fan Header Question

[Pez D Spencer]

This is kind of a dumb question but I like to do my homework before I buy any new hardware. I'll be getting my Q6600 in a couple weeks and I plan to use one of the Thermalright Ultima-90 coolers which requires you to add on your own fan. In the past I've always used heatsinks that already come with fans so this has never been an issue. The thing I don't understand is that any fan I can buy to add on to the Thermalright heatsink has either a small 3 pin connector or a big 4 pin molex connector. The CPU fan header on my mobo has a small 4 pin header and I wanted to make sure that it's gonna work with a fan that has a small 3 pin connector. What do you do just connect the small 3 pin connector on the fan to one side or the other of the 4 pin CPU fan header? If not, the only alternative I can think of would be to splice a small 4 pin connector on to the heatsink fan.

Also, the Ultima 90 HSF will accomodate two 92mm fans in a push pull setup which is what I'd like to do. In a setup like this, should I just get a y-cable and run both fans to the CPU fan header or should I put them on separate headers? If I need to put them on separate headers which should go to the CPU fan header, push or pull?

Thanks for any info.

 

[bretto]

I just got a Ultima 90 and I also have a motherboard with a 4 pin CPU fan header. I went with the Scythe Kama PWM 92mm. It is one of the only 92mm fans that I saw that has the 4 pin connecter. I'm almost positive that you can use a 3 pin fan without any trouble though, so just get whichever you want.

 

[eelw]

Yes, you can use a 3 pin connector on a 4 pin header. It's keyed so you can't install it wrong. The last pin is for PWM - pulse width modulation. With a 3 pin connector, SW fan speed adjustment is poor. It doesn't slow down in a linear fashion. The 4th wire does help fan speed adjustment better, but its far from perfect.

 

[NoobyDoo]

I had a similar problem. The only forum where I got a decent recommendation for 92mm PWM fans was here : Cooler fan vs Case Fan & 92mm PWM Cooler Fan .

See also : The Arctic-Cooling PWM fans are in and they work! .