I have a bit of a makeshift HTPC that I built as a side project a while ago, and I've found myself using it far more than I had expected. I actually prefer it to my Roku for the purpose of watching Netflix or Hulu on my smaller 32" 720p television. However, since it was a low-priority project initially, I really didn't invest time or money into making it as quiet as I should have. It's reasonably quiet compared to my actual full-function builds, but I would like to cut the noise down to something no louder than say, a PS3.
Unless someone would advise I need to change cases from my CM Elite 343, I have space for a 120mm front fan, 80/92mm rear fan, 92mm side fan, and a single slot pci exhaust. I also have space for a CPU cooler up 148mm/5.8" tall. I want to make sure there is adaquate cooling, and also would like to not spend a small fortune if possible. Right now here is the important specs:
Case: CM Elite 343
CPU: Athlon X3 455 (95w)
Cooler: Rosewill RCX-Z1 (runs @ ~66% speed/2000rpm)
Rear Fan: Silenx 92mm red Effizio (PCI controlled 1800-2900RPM- set to 2000rpm)
PCI Exhaust: Rosewill RFX-100 (rated 35cfm/26 dbi)
GPU: Asus HD 6670
Ideally, would imagine it best to run a only 92mm rear and 120mm front. Generally know that PCI and side fans are more audible. Also would consider a passive GPU if there was one certain to handle full HD video files- the onboard for my M5A88-M was a massive failure here.