8800gt fan header

[sonicbuddha]

This is a bit of a cross over subject into video, but, I'm planning on replacing the stock fan on my 8800gt with a Thermalright HR-03 GT and a 92 or 120mm fan. The only problem is that my motherboard does not have onboard fan headers. This is in a Mac Pro and, of course, Apple assumes (and discourages) any sort of modding. I was wondering if anyone had any experience using the card's four pin onboard fan header for powering non-standard fans and how to go about that.

Thanks.

 

[mpilchfamily]

Are there no free plugs on the PSU?

 

[sonicbuddha]

Honestly, I don't know but pretty much doubt it. This is a Mac Pro (2008), so its not really built with extras in mind and a hardware manual is not supplied. I can, however, start pulling things out and see what is exposed. That and look to see if I can dig up a manual at work (which is likely).

 

[DerwenArtos12]

One thing you'll have to keep in mind is the amp load of the stock fan is fairly low, so you're not going to want to put something like a delta on it or risk burning out the fan header. Second, the 4 pin power is PWM not standard voltage modulation so, you're going to have to get a PWM fan in order for it to function properly. Finally, the easisest way to make the adaptation is going to be to hack the end with at least an inch of wire attached and solder a male 4pin fan plug to it then the fan can just plug into that. I've done it several times with 2 and 3 pin video cards but, not yet a 4.

 

[sonicbuddha]

I hadn't immediately considered the amp load for a fan upgrade. Although it certainly would be more convenient approach to use the card's onboard header as well as utilize its heat sensors for speed regulation, overall, it seems a questionable approach. I've done some digging and I should be able to snake power from the molex connector meant for a possible second optical drive without too much wire weaving.

Thanks for the help.

 

[BassBomb]

Yea use a molex, I wouldn't use a motherboard header

 

[DerwenArtos12]

Originally posted by: BassBomb
Yea use a molex, I wouldn't use a motherboard header

Why not? if it's a non adjusable motherboard header it'll be stuck at 12v but, thats no different that plugging it into a standard molex adapter. If it's an adjustable header it won't be temperature adjustable but, still manually adjustable.