Computers And The Noise They Make

Weeden writes: "Here is a Salon article that wants to know why computers have to make so much noise. They think if the iMac can be quiet, why can't everyone else? Just do what I do and turn on some music, that makes the noise go away!" Quiet is certainly a concern for all-day computer users; I know I'd pay quite a bit more for a nice ATX case with a massive heat sink, if that were practical. If you need quiet now (and like the Salon writer, aren't willing to switch to an iMac) you might also want to check out this Ask Slashdot on the same topic.

Comments

x86 vs ppc

[T.Hobbes]

one main reason, so far as i can tell, that the imac can live without a fan is that its chip has far lower power consuption, and therefore generates much less heat that the x86 counterparts, and therefore require less cooling

Re:Noisy computers in bedrooms

[gargle]

If you don't need the computer at night, why not just turn it off? What does uptime do for you?

I LIKE MY NOISE

[Signal 11]

It's an important thing for geeks - how much fanage your system has. You know - it's like "normal" guys make huge garages and are measured by their piston count. Computer geeks, OTOH, are measured by how many fans and computers you have. If the lights don't dim when you power your baby up, you ain't worthy!

I got 2 120VAC exhaust fans, 3 HDD cooler fans, 3 more for the CPU, another for the GeForce, two intake fans at the base, a blower in one of the free expansion slots (two extra USB ports? who needs 'em!).. and that's just my workstation! Hell, my parents put me in the basement because it actually caused the walls to VIBRATE when I turned this beast on! Plus, I got two more fans on the switch.. another 5 inside the server box, 3 for the dev box, well.. 5 if you count the "minifans" I hung on the side, and I have CENTRAL AIR to my bedroom - yeah, that's right - when we were building this thing, I asked for 3 ducts into my room.. and shit, it still ain't enough! I'm wanting to get one of those RAID towers and some rackmount gear in here too.. I live up in minnesota and these dual-pentiums keep me nice and toasty down here...

Mmmm... more power... must cause brownout...

Re:Noisy computers in bedrooms

[drix]

I just took out all the fans in my case/power supply and replaced them with their equivalent "queit" version from here. They have standard 80mm fans which are way quieter. They also offer a silent power supply, but it's expensive and I have a feeling it's just a normal PS with a quiet fan stuck in it. You can do that yourself - easily. Also worth mentioning is their Silent Drive enclosure - I don't have one, but it's the mechanical whine of the hard drive that really bothers most people. The white noise of the fan is actually quite relaxing. I can't sleep in a room that doesn't have a fan going... besides, the smartest and cheapest thing to do is to just spin down your hard drive at night. It's easier on the drive.

Carpet, BTW, is a no-no. To make a long story short, save yourself a lot of trouble and do not do that. Ever notice how carpet becomes electrostatically charged easily? Ever notice how dust is attracted to carpet?

Riiight... now you get it :)



--

Re:Heat sources

[adolf]

(Score:-1, Redundant)

iMacs run hot, just as TVs run hot, monitors run hot, and most other vacuum tubes run hot. This says nothing about how warm the computer itself (which is placed below the CRT inside the box) runs. Gravity being what it is, heat rises and creates convection currents, and (in the case of an iMac) the chimney effect. Cool air comes in the bottom, warm/hot air exits the top. Just like it might if there were a fan in place, without a fan.

Incidentally, this is also a main reason why the primary cooling fan in a vertically-inclined computer exhausts air from near the top of the case, while cool air enters at the bottom (certain ATX 1.0-compliant power supplies excepted, due to stupidity on intel's part).

That all said, I'll attempt to identify some potential trouble-spots and some possible solutions for them:

The computer, as a whole. Heat reduction, damping and isolation are key (in that order).

Reduce heat by taking out everything that makes heat that you can get by without, and reduce cooling capacity accordingly.

To isolate it, move the box far away, and/or put obstacles between it and you. The Other Side of the Desk is a good option, or in a closet if permissable. The only reason you might need to fiddle with it with any frequency these days is to access the CD-ROM drive, and probably only then if you're a gamer, or you listen to audio CDs with the computer. If the latter, simply plonk out $50 (or less) on a cheap portable player and a patch cord from Radio Shack, and you'll probably enjoy superior sound at the same time. If you're a gamer, learn to deal with it, or crack your software to not require CDs to play, or invest in a multi-disc changer (which is handy, anyhow).

For damping, use Dynamat, which is an asphalt-based adhesive-backed compound which seeks to add non-resonant mass in quantities suitable for sound deadening purposes on light-guage sheet metal. Typically, it comes in a roll, sold by the square foot, and appplication is just peel-and-stick. It's a little pricey for what it is, and there are knock-off brands which probably work just as well for less money. It's important to note, however, that the adhesives used in Dynamat don't degrade with heat, and will probably stay attached until well after you're dead and buried, which is good. Buy it at your local car audio shop (don't worry, they all know what it is) or online at Crutchfield or Parts Express.

The purpose of this is to keep sound inside the computer, inside the computer, and/or kill it as it tries to leave, by making the large, expansive steel panels that comprise the cover of a computer much less prone to resonance. (Note to the more hardcore hardware hacks: This will require that you find, and replace, the top cover for your case.) Carpet pad, or wool carpet, or open-cell foam, or accoustic tiles, or anything else of that variety will not have an appeciable effect. These products all have their place, which is typically to provide a cushy surface to walk on, or a good accoustic enviroment - not sound isolation (the two are mutually exclusive). If your computer has its back to the wall, you might try placing some Sonex or Studiofoam on said wall to absorb some of the sonic reflection, but don't count on it being any tremendous benefit unless you've already done something about the sound travelling through the sides of the case.

Enclosing the case is probably not an option, though some here have suggested it. In enclosing it, you'll be eliminating your access to it. And also eliminating any external airflow. Add airflow, and you either a) create a path for internal noise to get out, or b) adding additional noise by throwing even more fans at it.

CD-ROM drives. The cheaper, the noisier (or so it seems). A LiteOn 32x ATAPI I have sounds like a jet turbine; in contrast, a 32x Plextor is more-or-less silent (but the newer 40x models seem to be louder). Solution: Buy a CD-ROM drive based on noise output, instead of data output and price. (Note that this will involve leaving the house, and possibly being social.)

Hard drives. Sure, you can put them in a Quietdrive box, which is just sorbothane (or neoprene) rubber, wrapped in open-cell foam and shoved into a plastic box with zero airflow, and they'll be quiet (and hot, dispite the marketing department's claims otherwise). In this case, however, more traditional methods may be best: Move the drives further away from your ears, and you'll hear them less. Use LVD SCSI, if needed for distance (and enjoy a performance boost, to boot). Else, you can try applying Dynamat to the surfaces that the drives mount to, trimming around all the holes. Do *not* put Dynamat or any other poor thermal conductor directly on a hard drive (even substances with "good" thermal transmission characteristics may block breather holes on the top of the drive, which is a no-no). Or, try to find a quiet hard drive. Not that this is any easy task. I used to think that IBM's 9ES series of 7200RPM drives were quiet, until I recently bought and installed a more recent revision and noticed that it was no longer the case (that installation, sadly, was in a recording studio). On the other hand, they're particularly cool-running drives, which alleviates some cooling needs. One other possibility is that Quantum (IIRC) claims to have a line of quiet IDE drives.

But, take all noise ratings with a grain or salt (or 20). They're usually expressed in terms of dBA, which is fine. However, they disclose zero details as to the measurement enviroment, distance from the measuring device, mounting to resonant surfaces (such as a computer's case), or any other factors which will have tremendous impact on such figures. If you want to get particularly anal about it, go to Radio Shack and get an SPL meter. The analog version goes on sale twice a year for something like $30. It will tell you exactly how loud something is at a given point. So, establish your a test procedure, and begin measurement. (If this seems like a silly thing to do, you're right.)

CPU fan. Personally, I don't see the big deal here, as long as you use your ears when selecting one (or trust the marketing folks). PC Power and Cooling is well known for their quiet, long-lasting, and effective fans. Alternatively, I've got a Cooler Master on a K6-2 which does the trick, making negligable noise. In contrast, a Global Win fan that lives on another K6-2 here out-whines the cheap Japanese hard drive, the LiteOn CD-ROM, Mitsumi CD-R, and ball-bearing power supply fan combined. Luckily, the DFI motherboard offers some sort of fan-control that speeds up the fan (in Windows) when there's significant CPU activity and slows down when there's not, but it still screeches like a banshee even when kicked down to low idle.

Rule of thumb seems to be that the bigger the heatsink, the higher the output of the fan which is attached to it. It doesn't need to be that way, but it is (*sigh*). In truth, the larger, or more dissipative the heatsink, the less air you need to have flowing over it. And, after you hit a certain point on size, you need no fan at all. CPUs these days can run *hot*, all day, every day, and continue to run at peak (rated) performance. You probably will need a fan if you're overclocking, but that's the price you pay.

In a normal system, the only things left are the one or two fans left on the case. If you have two of them, try disabling one. It costs nothing and doesn't hurt to try. Feel the top of the case periodically, both before and after the change, to get a rough idea of how it affects the internal temperature and plug it back in if you deem it too hot. If you need something even quieter, or require more than one fan for proper cooling, you can buy lower-output fans from Mouser Electronics, or a silent (but fan-cooled) power supply from PC Power and Cooling.

New machines _are_ quieter, here's why..

[knghtbrd]

Most newer off-the-shelf computers do not have a CPU fan. My Dell PIII doesn't have a single fan on that chip and you'd think it roasts to death. No way, it's cooler than the P200 sitting next to it that can be heard from the other room. If I shut dow that machine I can barely hear a whisper. So how do the new machines keep from baking themselves? Did Intel stop making ovens instead of CPUs? Certainly not. Intel chips can still get hot enough to fry an egg without proper cooling..! Maybe it's part of their patent or something, eh?

No, the reason is that the little fan that is stuck to the top of that P200 makes a lot of noise. The one in the power supply isn't exactly silent, but compared to the one on the CPU you'd never notice.

What this Dell and a lot of these quiet machines are doing is moving the fan off the CPU and putting it in the back of the case. If you just put a suitable heatsink on the CPU itself with some heat putty and snap a little plastic baffel over the CPU, what happens is that the bigger, higher powered, quieter fan in the back of the case pulls air in side the case under this baffel, over the heatsink, and immediately out the back of the case. This is an extremely efficient design.

The P200 sitting next to it pulls the air already over the heatsink off of it which supposedly adds to the circulation (though in my experience not very much) and pushes it into the middle of the case. Usually airflow is blocked by cables or something, so there's no real unobstructed path for the air to follow. Result? My P200 is quite warm to the touch. My PIII isn't cold to the touch (it's hot in here), but it's not noticably any warmer than the surrounding air temperature. Of course, add a petlier effect plate to that heatshink and watch the temperature of that chip drop below the room temperature.

So I guess the question is, are there any good recommendations for comodity cases with a similar duct design? This plastic Dell case works, but it's not expandable enough for a real geek. Not enough drive bays and the whole thing is plastic and not nearly as sturdy as the average $80 metal case, to say nothing of the nifty CalPC steel cases we all drool over.. =)

Quieter Cases

[oh shoot]

There are two things that make the Apple machines quiet: Efficiency and quality cases.

The iMac is silent because it has no fan. The CPU daintily sips power, whereas an Athlon or P3 guzzles it. This leads to very little heat, and thus eliminates several things: noisy CPU fans, case fans, and noisy power supplies.

The quality plastic cases on the iMac, G3, and G4 also do a fair amount of silencing noise. These cases are made of thick plastic that absorbs noise from fans and hard drives. One of the more frustrating things about my G3 is that it lacks not only drive lights (helpful when seeing if the machine is frozen), but also the sounds the hard drive makes.

How effective is the case? Try pulling open the cover that hides the CDROM, and notice the difference. The machine goes from just about inaudible to definitly there, but still quiet.

Compare this to a PC with a cheapo metal case that has a plastic front. Every sound is clear - you don't need drive lights, because the HD makes different noises for reads and writes.

The funny thing about quiet computers is that generally, you end paying more to get less (noise, of course).

--Jeff

My silent system

[dragonfly_blue]

I just built a server last week, and one of my goals was to make it somehow quieter than it had been. It was built from an old Compaq Deskpro a client had given up on, and when I got it, it sounded like a fricking airport. I record music with my computer, so keeping the volume level down has assumed some importance, especially since I have three or four computers going sometimes. Microphones are pretty sensitive these days, and digital recordings only serve to expose any extraneous noise in the environment, while analog tapes sometimes help to mask such artifacts.

Anyway, moving right along. I basically had taken the Compaq Deskpro apart, stripping it for parts, even took out the processor and the hard drives and cables, even the proprietary BIOS (which I subsequently had to hunt up of course.)

I had pretty much stripped the thing, short of taking out the motherboard, and chucked it in my basement for around 8 months until I remembered it.

When I rebuilt it, it took a while to find all the pieces, but I finally got it back together. Everything worked fine; I noticed it was a P-133 (not MMX) with a fairly decent heatsink on it. What the hell could be making that much noise??? It sounded like a wheezing tuberculosis patient.

So I snooped around a bit, and looked at it from a few angles, and lo and behold, it was of course the power supply fan. "Aha!" I thought to myself. "I'll just replace the fan with another, quieter fan!"

So after trying about four equally noisy fans (and lord only knows why they sounded like jet airplanes) it occurred to me that perhaps they were receiving too much current.

I'm no electronics expert, but I seemed to remember something about resistors (those funky little striped electronic thingers) resisting current, so I hunted up my box of spare parts, and tried throwing a couple of 'em on in series with the power supply fan.

Eventually I found one that was just right, and it slowed the fan down to that perfect balance, between putting out enough air current, and sounding like the Los Alamos Wind Turbine Hurricane Emulator.

I guess what I'm saying is; if you have an especially loud fan in your computer, why not just step the current down a little bit? Sure, it might not blow out quite as much air as it did, but you won't find yourself trying to figure out where that whooshing sound is coming from, either.

Probably won't work if your machine is overclocked though... ;-) In that case, get a Peltier instead. Or earplugs.