Quiet and Silent PCs

Right now, the most comprehensive site on the topic is The Silent Personal Computer. Also, the permanent URL of this page is probably going to be http://www.circuit-hacker.org/silence/. This location is very temporary, until I have my own server again. It is also probably that it will have broken links, since I moved it. If it does, let me know.

If I'm missing anything, or if you've managed to do something creative to make your computer silent, or if you just found this page useful, please drop me a line.

There have been several general approaches to making computers quieter:

Eliminating noise sources
Acoustically shielding noise sources
Seperating the computer from the user

All three approaches have tradeoffs. The first limits the performance of many parts of the system. In the second, it is very difficult to estimate final noise level. There is always a risk that after you finish, the machine will still be louder than you like. The third is not always possible. In making my computer silent, I focused on eliminating sound sources. I did this after I had spent some effort making my computer quieter, and found that it was still not quiet enough. With no fans and acoustic shielding, ant the drives usually spun down, I knew the system would be as quiet as technologically possible within my price range.

Most noise sources in the computer are fans used for cooling (the remaining noise coming from drives). Most types of acoustic shielding also form a nice thermal blanket. As such, there is an inherent tradeoff between noise and cooling. There is also a tradeoff between cooling and speed; higher performance chips inherently burn more power, and require more cooling. Most of the difficulty in making a computer quiet comes in making this tradeoff between heat and noise without losing too much performance. This comes from a combination of chosing low-power components, trying to reduce the power usage of existing components, trying to acoustically insulate without losing too much cooling, and trying to cool without making too much noise.

I've broken up this site into several sub-pages:

A general overview of why noise is bad. Contains some useful information if you wish to make a business case to your boss to reduce workplace noise.
Several companies now make quiet and silent PCs or kits that include everything to make a silent PC. These are no longer as overpriced as they used to be.
An overview of what I did with my PC and what I would like to do, given financial resources or sponsorship.
Some information on quiet drives, and making drives quiet
Information on quieting or eliminating the CPU fan
An index of quiet power supplies
Some information on acoustically shielding cases, including mufflers.
Low air flow and unfanned heatsinks are quite different from highly fanned ones. Some heat sink theory
Some fan theory
Several approaches to seperating the computer from the user
More radical approaches to cooling
Useful additional resources.