What measures can be taken to reduce the sound noise levels coming from computers (i.e. sound noise from fans, hard drives etc.) in an office space setting or home setting?
In my experience,
Replace crappy factory fans (CPU, GPU, and power supply) with quality fans. The bigger the fan, the better - a bigger fan typically needs to move less air than a small fan to produce the same effect (yes, I know it's oversimplified, but there you go.)
Replace video cards with passive cooled versions, or even get rid of discrete video cards entirely. If you don't care about desktop effects (office users normally shouldn't) you can lower noise levels considerably.
Not much you can do about hard drives as such (barring replacing them with SSDs, as pointed out by InSciTek Jeff in the comment below.) You can try improvising some rubber grommets and drive the mounting screws through them - I don't know how much that will gain you, though. Please don't take stupid advice like "reduce vibration by letting your drive hang freely in an improvised rubber band hammock" like this, otherwise you'll be in for a nice surprise the next time your foot, your baby or you dog bumps against the case.
Use a good case. I'm using an Antec P182 for my desktop. If it's possible to be in love with a case, it's this one.
Check silentpcreview.com every so often. Don't take it as gospel, though, they're sometimes partisan, and not all contributors are sane (see the HDD hammock idea above.)
This might not be the answer you're looking for but:
- Move your desktop box, under your desk (or further away from you.)
- Increase other sound sources... music or my favourite air conditioning.
At the office I can't hear my PC at all. Unless the air conditioning is switched off, then EVERYTHING sounds loud.
laptop CPUs - especially the new atom processors use very little power, and the fan can be configured to come on only when necessary (and at variable speeds). I have a netbook, and the fan rarely runs (only when I'm watching videos or something)
Solid State Hard drives are silent.
You could set up a 2 machine system where the noisy powerful machine is in the basement, and a nearly silent "thin client" remote-desktops to the powerful machine to do its work.
Soft rubber feet under the computer can prevent fan noise from transferring to the desk / operating surface.
There seems to be a wide variation in noise levels from DVD drives. Choose a quiet one.
Good options above. Other options (of varying sophistication) are:
Put the box behind a divider with acoustic dampening properties. You can buy these in studio sound equipment catalogs. Also, as I understand it, the standard office cubical dividers are intended to have similar properties, although it may be that cheaper versions don't bother living up to that.
The old-fashioned method: put the server in one room, access it with a nice quiet laptop or very simple terminal. Not so good for intensive graphics (although modern ethernet options and modern remote desktop protocols help), but with laptops like the iBook, or a true hardware terminal as once used in libraries etc., this can be VERY quiet.