Building a silent PC

Summary

The noise comes from moving parts, and vibrations caused by those moving devices and the flow of air trough the case and against the sides of the case. The easiest is to buy a computer that was built with silence in mind, either from established brands like Dell or HP, or from a local computer store where people know what they're doing.

But if you want to build your own, the noisiest parts are..

Needless to say, get reputable brands...

And if you want to get furter...

Main manufacturers

Whole PCs

Cases

Power unit

CPU fan/heatsink

Fans

Hard drive

Contributions

Disk drives

Contribution: I recently bought a Molex Silent Drive (http://www.silentpc.nl/prod04.htm), it reduces the hard-drive noise by more than 90%. This is really great!

Contribution: The best way of course is to use quiet HDDs like the Fujitsu-Models (the new ones are even fast!).

Contribution: There are three ways to make your HDD shut up: encasing it in a noise dampening box (which may cause heat problems), make it heavier (this is usally done by using heavy metal coolers) or hang it in rubber strings (to prevent vibrations to be transmitted to the case).

CPU

Someone mentionned using heat-absorbing paste on the CPU, a huge heat sink on top of it, and a small CPU fan to cool the CPU. Added to this, removing the fans to cool the PC box, slowing down the CPU and the power supply fan (with a 100 ohm resistor), and quieter hard disks from Western Digital. Molex makes very quiet CPU fans.

Fans

Exchange all coolers against temperature controlled models.

PSU (power supply unit)

Get them from either QuietPC or Enermax

PC Case

High frequencies produced by your HDD and the coolers are amplified because the noise is easily reflected by the metal surfaces in the case! Use noise deadening materials to kill these reflections and vibrations.

For the adventurous, water-cooled boxes (more infos at http://www.overclockers.com/) from eg. Koolance.

I personally bought an Ultra Quiter PSU, SilentDrive hard disk enclosure and Radial Fin Cooler, all from QuietPC, and am very satisfied with the result. I can still hear the computer humming, but once I replaced those noisy parts, I realized that now it's my keyboard that's too noisy :-) If only computer manufacturers built silent PCs from scratch...

Food for thought

From Methods to Silent PCs by Tomas Risberg

The easiest way towards a silent a PC is of course having it build silent from scratch. This is easiest accomplished by excluding as much as possible of mechanical parts.

The hard drives as we know them today must contain mechanical parts, so we might have to accept them as mechanical, at least for the nearest future. Today the storage industry competes on making the most silent hard drives, but by using today's techniques for building hard drives they are seldom quiet enough. A common solution to this problem is to put the hard drives in sound absorbing boxes. Sometimes this solution is also used for the whole PC, which is put in a  big sound absorbing box.

Fans, as said before, are often needed to cool the electronical components of PCs. One way to avoid fans is to build a PC with electronic components that produce as little heat as possible, or/and taking advantage of the physical properties of air and other materials, thus making the fans unnecessary.

Some electronical components, this is especially used for the processors, can be sufficiently cooled by attaching heat sinks to them. If needed, when carefully designed, fans can be built to run quiet.

The electronic circuits of the PC can also be designed to continuously measure the critical components temperature, and according to the needs for cooling regulate the fans speed, so that they only are used as much as they are wanted and not more. An other but troublesome and expensive way to cool PC components, and sometimes also make the cooling more quiet, is to use other and more effective media than air for cooling purpose, such as water.

Lastly a method to have a silent PC is to put the whole machine as far away from the user as possible. Problems that might arise using this solution is foremost related to costs, space, and keeping the quality of the screen image intact using long cords. A solution to this might be future radio or IR connected screens.

From http//www.fullon3d.com/hardware/articles/0499/heat

The three main sources of permanent noise from your computer are harddisks, fans and your speakers. Assuming that you were careful with your harddisk(s), the power supply and CPU fans are the two worst hooligans. The direction of the noise they produce usually are at a 90 degree angle from each other the way they are pumping the airstreams is where most of the noise travels along.

In the case of the power supply fan this is from front to back (fan blows out) or back to front (fan blows in), with the latter being less noisy usually as the noise is caught in the power supply first, computer case second and doesn't get far from there.

Socket CPUs

The CPU fan on the other hand is sitting perched on the CPU, which means that it is blowing air from the left to the right or right to the left. The solution that makes the most noise in this situation is the one that blows from the CPU to the side of the computer case, effectively using that sheet of metal as a resonator that amplifies the fan noise, albeit somewhat filtered. If it blows the other way, the heatsink and mainboard will catch the brunt of the noise and reduce it that way before it can escape.

Slot CPUs

On Slot 1 and Slot A CPUs, the fans are attached to the chip's protective casing or the CPU board and cool both the CPU and the L2 cache chips. This is a more favourable angle of attack regarding the sound problem since air moving to or from these is not hitting the case sides and hence tends to get swallowed up in the main air stream coming from the power supply or bounces off the add-in boards.

A potential problem is located with add-in boards receiving a lot of warm air, heating them up while they are really passive, but this only applies for a low throughput fan that can't shovel a lot of air onto the heatsink(s) and nearby boards and only if the fan is facing the boards in the first place. Secondary noise can be generated by whistling along add-in board edges or elevated circuitry, sucking noises of air that streams into the case (if a fan blows waste air out) or bad bearings in the fans that generate vibrations in the box, this is often the case with cheap cooling fans, if not from the start then after a few weeks of grinding plastic to dust. So your ideal CPU fan will have good metal or glass ball bearings (i.e. a Pabst fan), low-noise fan blades and a non-whistling heatsink and blow air into the heatsink instead of sucking it through the teeth.

Q&A

How to use lm_sensors on Linux?

# sensors-detect

# sensors

SFF?

Small form factor, ie. the cube-shaped computers such as those from Shuttle.

BTX?

BTX - Balanced Technology Extended (BTX) Form Factor, FIC BTX motherboard and Aopen Cases

Temp

Si ton processeur  ne dépasse pas le 1,4 Ghz : Ventilateur Molex radial fin 37165 Pour les disque dure : Silent drive (ca enleve le bruit de turbine des disques mais pas le grattement quand il travaille)

Ce que tu as fait...mais en changeant de DD pour un plus silencieux. Ou bien isoler le boîtier au Gedicoustic, et monter le DD sur silentblocs...mais en aucun cas l'envelopper dans de la mousse, faut qu'il respire!

si tu ne veux pas acheter de noize blocker (cartouche silent drive dans lequel metrre ton DD 40?), il n'y a plus que la soution avec caoutchouc dans un emplacement 5.24", tu dois pouvoir en faire un toi meme avec une chambre à air ;)

Oui : j'en ai calfeutré toutes mes machines ou presque (4 sur 5). Mais il faut quand même que ta machine soit bien ventilée. Pour ça pas de mystère : un ventilo à l'avant, en bas, un autre à l'arrière en haut...et penser à boucher tous les trous "annexes" pour orienter correctement le flux d'air. Et aussi virer les grilles en tôle découpée qui se remplissent de poussière et ne font que freiner l'air brassé par les ventilos...

Sur www.rue-montgallet.com comme sur www.rue-hardware.com , la bonne technique est de vérifier le nombre d'étoile mis par les *clients*.  Pour cela, cliquer sur "boutique" dans le bandeau bleu foncé et vérifier la nb d'étaoile : en dessous de 4 ne PAS y aller. Qq boutiques sérieuses : UltraMédia, Prowares et FuturPC (3, Rue Ebelmen 75012 Paris 01 43 40 23 38).

Pour un PC aussi silencieux que possible

Choisir son processeur : avec économie !

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