So I'm not the blogging type, but I thought this topic was worth the time for your consideration.
I have a home-brewed computer that's about 8 years old - and one of the real pains about computers and many other mechanical devices, it that they create noise.
My computer had this nasty habit of wearing out fans - or more precisely creating noisy fans. Most recently, the power supply fan had developed excessive noise - not the squeal like you get when the bearing is going dry, but kind of a rattle - like when something gets loose and, well rattles.
The Northbridge fan did develop the squeal that I could eliminate by loosening a mounting screw - but the fan still made more noise than I thought appropriate in a studio.
So I set out on a search for ways to make my computer quieter.
After considerable shopping on-line and at a local Microcenter computer store, I discovered the Seasonic X-400 fanless power supply. The review at http://www.silentpcreview.com/Seasonic_X-400_Fanless_PSU
gave me confidence that the Seasonic X-400 was a worthy power supply.
As for the northbridge cooler, I discovered a number of fanless heat sinks specifically designed for the northbridge chip set did a quick evaluation of the existing heatsink and determined that by removing the fan and reorienting the fins for maximum convection and airflow that it would suffice.
For the results of the noise test please listen here.