Building a Dead Silent PC

Jouster writes "The folks over at HardCoreWare.net have finally lost it. They built a PC that's well over twenty times quieter than their comparison PC (40 dB versus 65). And it's no sluggard, either: P4 2.80 GHz, 7200 RPM hard drive and--get this!--an overclocked to the max GeForce4 Ti 4200! The only fan in the entire system is in the PSU."

Re:20 times quieter?

It's a logarithmic scale. The volume of the sound goes up ten times for every ten decibels. Here's some math [wolfram.com] and a comparison chart [everything2.com].

Re:20 times quieter?

sound is measured in terms of power intensity... W/m^2 and is converted into decibels by taking the logarithm to base 10 and multiplying by 10... i.e., 10 log_10 (X)... so 3 dB is a doubling in sound intensity (not 2 dB)

Re:20 times quieter?

mod this one down plz!!!

+10db is twice as loud to the human ear!

So the 65 db down to 40 db should be something like 5-6 times less loud to the human ear!

Its the energy that is 10 times as big when you go up 10db!

Example:
A 10W stereo plays x db
A similar stereo with 100W plays x + 10 db
A similar stereo with 1000W plays x + 20 db

Re:20 times quieter?

+10db is twice as loud to the human ear!

You're right, but I'm not wrong. For a full explanation [slashdot.org]

Re:20 times quieter?

Please explain how something can be 20x quieter...

Decibels is a logarithmic scale.

So 10db is 10x (power), 20db is 100x and so on.

This might seem like they are understating the case, but in general 10db is considered to sound like "a doubling in volume" so a difference of 40db is roughly 2 to the 4th or 16x.

Fiddle with a few db more and you can easily justify "20x quieter."

Re:20 times quieter?

HAHA its so true. I just read another post i was goign to reply to but saw you so let me go off here. The wattage of a stereo doesn't matter. Its does matter in that its part of the equation but not the total measurement. I have seen peizo electric and other speakers that run off fractions of a watt that can put out over a hundred decibles. I hate all this crap about "i have a 500w stereo, oh yah well mines 600w". Some speakers can make it up to 130dB but will start to distort at 110dB, where as some wont distort up to 115dB but can only go to 125dB. Which one would you rather have? Im tired of people doing stupid things with speakers. Running 1kw systems in their drunks using $5 cables that have way over acceptable limits of capacitance. And dont even start on capacitors they sell for subs in your trunk. Thats just total bullshit. When the sub runs out of power its because of impedance on the line most likely from bad connections (solder em if you really want good sound) or just plain bad wires (10 gauge wont cut it). Personally im going to stick with my mono radio output and take the $1000 i saved and do something better.

Re:20 times quieter?

Please explain how something can be 20x quieter...how does this math work?

It doesn't. Something can't be 20 times less than something else. You can either have something which is 1/20 as quiet as something else or something which is 20 times LOUDER than something else. It is complete nonsense to talk about something being 20 times less or 20 times quieter.

This is a common mistake which people make, you can see it all the time even in professional settings. You will often see people saying stuff like, "This will be three times less costly than other solutions." It's a sad state of affairs but I think that math skills are seriously deteriorating.

Sound from the computer

If you can hear the sound from your computer its a sign that your music is way to low

Not as loud, but its still a space heater

Those who forget the apple are doomed to reinvent it. Apple has been using large heatsink, air flow design, etc for ever since the blueg3 to keep there from being too many fans in the system.

However, an Apple still puts out much less heat overall and I notice the article didnt even try to find a quiet cdrom. I have 2 in my PC and both are loud as the dickens.

Re:Not as loud, but its still a space heater

And what aboutthe floppy drive? Those things are rarely used these days, but can be terribly noisy.

Easy: take it out. Since last year, I've been building PCs sans floppy drives. IMO, floppies have very little use these days; files are regularly larger than 1.4 (or 2.8) MB, making floppies pretty useless. Most modern BIOSes can boot directly from CDROM. I've been using USB flash drives (a friend has a "pen" style, I like to use Compact Flash w/ a USB adapter), they're faster, and to the topic, make no noise whatsoever.

I remeber taking over the lab to download the 20+ floppies for Slackware back in '93...

Silent iMacs and Monster Heat Sinks

The slot loading "original" iMac (aka the gum drop) had(has) no fans, quite hardware, and vents on the top of the case. I don't quite know if Apple's eMacs and LCD iMacs have a similar set up, however I'd bet that they have fans.

Nevertheless, Apple still strives to build fairly quiet boxes when ever possible. I mean hey, look at the fan to heat sink ratio in this box: http://www.apple.com/hardware/gallery/pmg4_august2 002_480.html Honestly, I've never seen a bigger heat sink within a consumer PC. One could fry 10 strips of bacon on that beast.

Re:Not as loud, but its still a space heater

"Those who forget the apple are doomed to reinvent it. Apple has been using large heatsink"

Who said Apple invented large heatsinks,airflow design, etc?

I have been using large heatsinks, low powered quiet ducted fans, and passive coolers since the pentium days. My current machine has an 80x80mm heatsink with copper base embedded in it with an 80mm silent fan and its cooling an athlon XP 2100. The rest of my system is setup such that I have minimal airflow for the required cooling. Ducted air, large heatsinks, copper bases, etc etc..

People have known about large heatsinks, passive cooling, etc way way way before Apple Computer started making PC's with passive heatsinks on it.

Also, your post is irrelevant considering that Gateway, Dell, HP, Compaq has been doing the exact same thing in (many) of their systems as well for years. (check out dell optiplex, Gateway E-series, I dont know the compaq models, but I have seen some like this).

Then consider the G4 cube. it was fanless, nice innovation. But then they put a loud as hell hard drive in it, the power switch went off intermittently due to overheating (it was heat sensitive) and they put a fan in it anyway when they put the 3D Video cards in it. (this video card fan was like a 40mm fan spinning fast as hell and it was not very quiet at all, all on top of a very very small heatsink which had plenty of room to be larger)

Next, you are going to tell me that Apple invented thermodynamics? Please. Don't try to pretend Apple invented everything. They didn't. And they are far far far FAR from the ppl who started making silent PCs. Everyone has been making silence (and mostly, reduced noise) since the begining of cooling weather it be for cars, power lines, space shuttles, oil pipes, computers, whatever.

silence overrated?

i used to always strive to quiet my computer more and more, undervolting fans to 7v or 5v, i had my p233 absolutely SILENT, except for the loud hard drive.

but now, building my new system, i have 4 moderate (sound) volume fans, but they really dont bother me. they produce a calm whir, and they're actually kind of soothing at night :P

but the whole silent pc thing isnt all that hard, really. just put in some panaflo L1A's (undervolted if necessary), a seagate barracuda IV, and you are good to go. i dont see why people go to such extremes, for little to no improvement.

Re:silence overrated?

i dont see why people go to such extremes, for little to no improvement.

It's called the noise floor, and while it may not matter much to you in standard computing environments, it matters a lot in non-standard ones. Like if you're building a home theater PC. If your PC runs at 40 dB then forget hearing anything below that -- which can be either quiet passages in music (classical or rock - both have 'em) or downkeyed scenes in movies. Turning the volume of the system up isn't an option unless you want to constantly change the volume during a movie so you don't lose your hearing during action/climactic scenes.

Additionally any noise like a PC can interfere with subtle nuances in music or movies, which is equally bad. With a 20 dB noise floor you may be able to hear sound queues for things you can't hear with a 40 dB noise floor.

So it's not little to no improvement - it can be pretty substantial in the right environment. Personally I'm looking to build my next PC to be quieter, not because it's going to be a HTPC, but because I'm tired of having an absurdly loud PC. I'm not going to take it to extremes, but I will try to purchase quieter components.

I have to wonder......

exactly what this will do to component life. As you can see from the graphs they posted, the CPU and graphics card do run noticably hotter than with the stock cooling.

To me, the small amount of noise created by a the stock CPU fan and graphics card cooler are worth the bit of extra noise.

A very quiet case fan might be a good addition to this to help draw heat out of the case. That big plastic window doesn't help add anything to radiational cooling from the case, either.

And my athlon isn't *that* noisy, especially when it's tucked away underneat the desk.

Re:I have to wonder......

Radiant heat transfer is on the order of 10-100x less effective than convective cooling (like with a moving airflow). Radiant transfer varies as the fourth power of temperature, and does not turn significant until you get to temperatures that would a) fry any component you can name and b) give you a really good burn when you accidentally brush it with your leg.

So the window, apart from looking stupid, doesn't really hurt anything. : ) 'Cept the faraday cage.

Re:I have to wonder......

Semiconductors aren't that sensitive to moderate heat, in the way that it would destroy them; if they get too hot, you will just have system crashes, random resets, etc. (as if that isn't bad enough).

No, but heat kills bearings. So, the hard drive will probably be the first component to fail, especially with today's sensitive drives.

Another mid-term problem would be the electrolytic caps. They will dry up over time, which will introduce sporadic instability/reboots at first, and you'll be driven mad searching for the cause. Almost impossible to detect without special equipment, i.e. an ESR meter.

So, if you want a silent PC, you'd be better off buying cool components in the first place. It's just too much of a hassle (and expensive) trying to silently and reliably cool high power CPUs and graphics cards.

ESR meter

Almost impossible to detect without special equipment, i.e. an ESR meter.

If you do decide to get one, just remember not to put it next to your RMS meter. they'll both get totally out of whack.

Quiet PC?

Yeah, it's called putting a PC in another room and accessing it via vnc/ssh. You won't hear a thing.

Longevity? Hardware Burnout?

I think it's great that these guys did this, and I'm quite impressed at the hardware statistics and performance for such a quiet system. Although, there is a conspicuous lack of one element from the whole article...

Longevity.

While I've been desperately wanting a completely quiet computer that runs decently for some time now, I don't have the money to invest in a solution that is going to last only for a year or so. I guess I wish these guys had done more extended testing of their system.

Has any other /.er made a comparable system? How has it lasted?

Maybe I'm just a skeptic, but an overclocked GeForce 4 Ti with no active cooling makes me anxious, and somewhat hesitant.

Re:Longevity? Hardware Burnout?

My solution to making my PC quite was very simple: I built a big-ass sound-insulating box for it. The box itself is made of particle board, lined with acoustic ceiling tile and carpet. I cut fan holes in the side of my original case, and mounted three fans to blow directly onto the CPU, memory and graphic board.

The fans on the side of my case pull in air from a 20" long carpet-lined duct--it acts a lot like a car muffler. The air moves through, but the carpet absorbs nearly all the sound (the sound needs to make two 90 degree turns to escape the air channel). There is a similar duct in the back of the case for outgoing air.

My 'new' case has more airflow than the computer originally had, so my internal temps are only a little higher than they used to be. I built the box with a weekend and ~$25. Now I can leave my computer on all the time without making my ears ring. If you've got access to a wood shop, it's a very effective way to make a quiet PC.

Most Apple products have been silent.

Most Apple products have been silent.

Its one of the main reasons people like to buy them.

Even some of the G4s (cube) keep the fan off unless critical.

powerbooks are similarlysilent unless emergency fans kick in.

The balance of other modesl, such as imac are designed with columnar "chimney effect" air flow out the tops.

And many famous apples have no fan at all whatsoever, not even on powersupply : Apple II, IIe, IIc, IIgs

Many musicians like the newer macs with sampler gear because they don't have to worry about systyem sound so much.

External D/A in usb allows noise free amplification far from motherboard on most all mac models in last 3.5 years.

Mac lovers hate noise it sems.

I wish dual cpu AMDs could be made much quieter.

I can think of one idea to get even cooler

Those are some gigantic heatsinks. The processor heatsink alone is frigheting enough. But there does seem to be one solution that can be even quieter and can cool both Pentiums AND Athlons...

Water cooling! [koolance.com]

It's certainly different, using water to carry off and circulate the heat. Obviously, it requires a large degree of trust, as one leak can short out your entire system in a heartbeat. I've been around these beasts, and they certainly seem quiet enough.

I imagine they would be great for overclockers :D

Re:I can think of one idea to get even cooler

No.

Heat exchangers want to maximize surface area, not mass. You are trying to present the maximum surface to the surrounding airflow, cooling by convection. More mass would simply be a thermal battery, storing heat on the processor. The thin heat sink fins actually remove heat from the processor by transferring it to the surrounding air.

Re:I can think of one idea to get even cooler

There's one more aspect to that. When you have very thin, long fins, like the Zalman heatsinks do, the thermal conductivity is too low for the heat to be transfered all the way to the tips. From what I can see on the photos, these heatsinks are not as efficient as they could be. IMHO the optimal heatsink would have a tree-like structure, whith thick 'stems' conducting the heat to many thin, but reasonably short 'leaves'. The Arkua [arkua.com.tw] coolers seem to somewhat follow this approach.

Old news

The PowerMac G4 cube [apple.com] (bottom of page 4, "Noise characteristics") was only 31 dB. That's 2,512 times quiter than this "silent" PC.

Re:Old news

2,512 times quieter than the 65 dB machine:

10^3.1 = 1,259
10^6.5 = 3,162,277

3,162,277 / 1,259 = 2,512

Re:deciBells

I'm not sure where this 20x quieter thing comes from, but generally. a 10dB increase in sound output is considered "twice as loud." Note that a 3dB increase is twice as much energy (well, 3.0something, but close enough). Similarly, -3dB is the "half power point."

Your physics teacher will tell you that 10 dB is a 10x difference in the intensity of a sound wave.

Your psychology teacher, or your friendly local audiophile, will tell you that a 10x difference in wave intensity is only a 2x difference in perceived loudness.

Most slashdotters, geeks that we are, payed more attention in our physics classes. As a result, I forgot about the perception issue until just now.

I am currently listening to 128 kbps mp3s on a $25 pair of headphones. Whether or not I am an audiophile is left as a exercise to the reader.

Explanation of log

Here, once and for all, is a log scale mathematics explanation. I'm still a student so I remember something about it:

Sound level is how loud a sound is to human ears. It can be measured in dB and an increase of 10 dB sounds ten times louder to human ears.
Sound intensity measures the energy of the sound, often in W/m^2. (Watts per metre squared.) If you multiply the sound intensity by the face area of your eardrum, you'll get the number of Joules per second (W = J/s) that your ear is perceiving. This scale is linear with human hearing perception, so double the intensity means it sounds twice is loud.

The Equation:
B = 10log(I/Io)

B = sound level in dB
I = sound intensity in W/m^2
Io = sound floor of human hearing, Io = 1x10^-12 W/m^2

So, doing the math, 40dB = 1.0 x 10^-8 W/m^2.

And 31 dB = 1.26x10^-9 dB

So therefore, 40 dB is 7.94 times more intense, and therefore 7.94 times louder to human ears.

(7.94 = 1.0 x 10^-8 / 1.26x10^-9 )

Note: the previous poster's comment about one being 2,512 times quieter than the other was for different values, and this information does not override that person's (correct) calculation.

Thank you, and have a nice day :-)

Great news for Beowulf clustering

According to my calculations, you can now cluster 100,000,000 PCs before their combined noise level reaches the threshold of pain!

Confusing headline...

My first thought was "Isn't a dead computer already silent?"

-A

Re:Confusing headline...

[haleyjoel]

*clinching blanket and pulling it towards face*
"I can hear dead boxen".

[/haleyjoel]

Already been done

See here -- it's GOT to be silent. [cynikal.net]

Also, ever hear of that new lampy thing called an 'iMac'?? Yeah, they're silent.

Google Cache

here [216.239.39.100]

Noise Cancelling Case

It seems to me that someone would have come up with a noise cancelling method by now. You know, something similar to the technology utilized by some headphones such as these [aiwa.com] by Aiwa. Basically you could sample the sound inside the case then invert the wave, and then play it back through a case speaker. Viola! Instant nose reduction. This would also dynamically address other noisy things such as cd-rom drives. Just an idea to make millions. -peel

p.s.- If you don't understand how this works you can also try it out with your home stereo and a song with a lot of base. Take your speakers and aim them at each other then take one of the sets of wires and switch the positive and the negative. You will notice the sound of the bass reduces dramatically due to an effect called phasing.

Re:Noise Cancelling Case

Unfortunately, general noise cancellation in three dimensions is a much more difficult problem than noise cancellation at a point or two (e.g. headphones).

I can't do that

I sacrificed the possibility of a quiet computer when I chose an AMD 1500+ for the CPU in my computer, so now I've gone to the other extreme and been proud of just how loud my PC runs. What I really want is a diesel generator that I can use as a long term UPS because then when I want to show it in top form I can just pull the pullcord and it will be the loudest computer for miles around. Also, I will put a fart can on its exhaust system, I hope the cops don't catch up with me for my modified exhaust.

What about fluids?

This is quite timely, with the release of Windows XP Media Center Edition [microsoft.com] creating the need for a silent box that won't detract from that $2000 sound system! They use mostly Zalman Tech [zalman.co.kr] heatsinks in this system for noise reduction, but I wonder whether air cooling will continue to be viable in the next few years? Fluid cooling systems were necessary for the Cray supercomputers of the 70s because of superior heat transfer characteristics. This may be the case in the near future if silicon densities increase much further. But fluid cooling is also good for silence as well. The LA-class fast attack submarine that I was on for a while used a chill water cooling system for the sonar display equipment. And you can imagine how much silence is paramount in that setting! (Of course, they also used magnetic rotating drums for display buffer memory, if you can imagine...)

"I've still got the scar"

Zalman CNPS6500A-Cu: $50
Zalman ZM17CU: $18
Thermaltake 420AD: $60
Seagate Barracuda: $80
Thermaltake Xaser II: $100-180
Being able to ditch the hotplate, and just warm food on your casetop: Priceless.

So what?

So some guys with a website bought a bunch of large heatsinks from other companies, built a computer that uses almost entirely passive computing and we're expected to do what? Commend them on their innovative use of a credit card? ;)

And it's not like super-quiet computers haven't been done before. Yawn. Boring.