Getting rid of PC noise has been a sort of religion to me since my pc is right next to me on my computer table. I use anti vibration padding in my case and have anti vibration feet.
My fans have a sort of anti vibration strip to reduce noise and I tend to avoid overclocking, since I do not trust watercooling.
I cannot stand a loud PC, after using my old Mac for nearly six years now. It only has two or three fans from what I have seen, yet, because they are Deltas, they are VERY loud. When I had my Centurion 5 (broke, replacing with a CM690) and I set Silent Mode in the BIOS, I gradually got annoyed, it was still too loud, even though it was virtually silent.
I grew up with loud computers. One of my first PCs was a 486SX-25 Mhz with 2MB of ram. The power supply on that thing had bad bearings on the fan, and it made the loudest rattlely sound; but it worked. I loved that computer. It didn't matter that it made noise.
Before that, I had an apple][c that made the most god awful noise when you turned it on with out a 5 1/4" floppy in the drive.
My printer was a dot matrix.... If some of you young guys don't know about those sons of bitches.. it is purely impossible to describe the sounds that emanated from them... and if you though one was bad; My elementry school computer lab had 10 of them, sometimes all going at the same time. AAUUGGHH
While times have changed over the years, I still have to be able to hear my fans spinning to let me know that it's still alive. When I recieved my Corsair HX620 , I thought it was dead. (It's so damn quiet.)
Sound doesn't bother me, because it can't be as bad as it used to be.
PC noise doesnt bother me at all. Heck, with a Cobalt running 24/7, my machine (2 vantec tornados), a window AC unit, as well as a Proliant DL680 server (rated at 150CFM and 1750BTU) running 24x7 right next to my desk which is less than 5' away from my bed I cant hear my PC anyway.
Anyway, like negative decibel below, I grew up around dot matrix, and loud machines... Plus in my work I deal with noise all the time, so I just dont care. It gives me a reason to crank up the music and the gaming bloodfest in 5.1 surround sound.
However, on the rare case I do voice chat or recording, I kill the proliant and the window and slow down the tornados then it gets really quiet... Gotta keep the Cobalt running though, its the server serving my site.
im trying for as quiet as possible, which is why i have migrated from a fleet of clones, to a fleet of business desktops. each of them *individually* would be nearly sillent, if used one at a time or in seperate rooms. however, once you get them all back together, they start to build on each others Db's.
i would say tho, that my rig now, is about as loud as my old Dual p3 was (golden orbs, with 4 ultra160 SCSI drives, during the advent of "cut-hole'd casefans", and i called my "jet engine computer") from back in the day. so for 8 computers always on, its not too bad.
Noise doesn't really bother me all that much... I've worked in loud environments my entire career, so I suppose I have just become acclimated to some level of "background" noise..
I overclock moderately, and I used to really not mind the noise from my PC. Louder somehow meant faster? Lately though I've been concentrating more on choosing quieter components, and at this point, my desktop is almost as quiet as my laptop!
My PCs are fairly quiet, but my servers are anything but. I have a 1U that isn't too bad (don't really notice it that much with music playing) and a 4U that makes some noise... I.E. you have to talk a bit above normal to hear well when it is on (24/7, except now because I'm moving back home for winter break )
The noise doesn't really bother me, kind of comforting actually... Lets me know my shit isn't broken
I want a good overclock and I don't worry too much about noise. I used to have a system with an 80mm Tornado and a 92mm Tornado in it. That system was about 3' from my bed. I ended up getting a Koolance EXOS system and pulled out the Tornados. Two weeks went by before I was able to sleep decent. While it wasn't silent by any means, it was a lot quieter than what I was used to and that worried me.
Right now I have five systems running in the same room. You're going to have noise from that no matter what you do so I just don't worry about it. Besides, there's always something else running making noise in my apartment so it's not like it's that big of a deal. I just turn on some music or play a game and I don't notice anything anyway.
The loudest fan I have in my computers is probably a 60mm 5k RPM Thermaltake fan. One of these days I'll get around to replacing that heatsink with an 80mm one that cools better and will be much quieter. However, overall, it's not that bad.