I've always wondered if there were better ways to cool your GPUs. Even with the custom cooler on my Gigabyte Windforce GTX 670, it idles around 55C when I have the fans set to the minimum speed. As some of you may already know, I'm VERY picky about noise, but what can I do to keep my GPU cooler and keep noise down? Well that's when I thought about using the stability of PCI slots on the case to mount two fans right beneath the GPU to assist the GPU fans!
I looked around the internet and found a cheap PCI fan mount for ~$6 on "the bay". It was designed for 80/92mm fans so the holes aren't quite perfect, but it is designed very well and can easily be adapted for 120 or 140mm fans.
Here are a few pictures of what it looks like after everything has been put together:
Notice the screw holes for the brackets don't match the fan so I used bent paperclips to hold them together. I've actually switched to zip-ties which work a bit better.
Here's how it looks like when installed in my case:
Notice it fits perfectly too! Both of my 800rpm Scythe Slipstream fans cover almost the entire length of my GPU.
Now for the most important part - temperatures and noise level. Sorry I don't have anything to objectively read the noise levels, but I can tell you the differences is dramatic.
Here is some approximate (+ - 2C) temperature readings using Speedfan:
Idling 20% fan speed of GPU:
GPU only: 55C
With fans @300rpm: 45C
Noise Level wise, they are both the same. But notice temps drop a dramatic 10C!
GPU only: 72C
With fans @800rpm: 63C
Again, we see almost a 10C difference! Because of the custom fan curve set for my GPU, noise levels were similar, but the cooling is very different. In both tests, my GPU can run under 20dB, but when playing games for long periods of time, the GPU gets much hotter so the fan do kick up and get loud.
By using this cheap, yet very effective method, you can cool a GPU dramatically yet keep noise down. This is a MUST do if your case has enough room!
My mirrored thread on OCN to see pics better: http://www.overclock.net/t/1355164/ohhgouramis-gpu-pci-fan-mod