Build a quiet(silent) PC Dec 2009

I have an article written up with my current silent computer configuration.  I have every part mentioned here except for the case.  The article can be found at  http://asecurepc.com/wiki/doku.php?id=build_a_silent_computer.  Price and parts are included to illustrate that a silent computer does not have to be expensive.

As of Dec 2009, I have made some additions.  Talking to a friend, I learned something new about computer noise levels.

It has become apparent to me that 5 fans making 19DBa (decibels) of noise does not make 19dBA of noise, but 26DBa (decibels) of noise.  Therefore, in order to minimize the amount of noise, minimize the number of fans.  Furthermore, a closed case is quieter than an open case.

A simple DBa (decibels) calculator can be found at http://www.anvtech.com/cgi-bin/db.pl

For those that have MS Excel, Open Office Calc or some other math program, this can be typed into the program to calculate the computer fans noise level. Taken from http://episteme.arstechnica.com/eve/forums/a/tpc/f/77909585/m/3120945705.  For each of the B1, B2, B3, …, put in the dBA(noise level) of each fan.  For example, =10*LOG(10^(19/10) + 10^(19/10) +10^(19/10) +10^(19/10) +10^(19/10) +10^(19/10) +10^(19/10) +10^(19/10) +10^(19/10) +10^(19/10)) in MS excel gives 29 dBA of noise.  This is assuming that I have 10 fans that have a dBA of 19.

=10*LOG(10^(B1/10) + 10^(B2/10) +10^(B3/10) +10^(B4/10) +10^(B5/10) +10^(B6/10) +10^(B7/10) +10^(B8/10) +10^(B9/10) +10^(B10/10))

I have a silent computer. Unfortunately, it is not very pretty.  I did not realize that you have to purchase a special case to hold the larger intake and outtake fans.  I still managed to get the parts to fit, but I used a bunch of twist ties to hold them in.

If you want to see what my computer looks like, you can see the pictures at http://aprivatebeach.com/blog/2008/11/custom_silent_computer_pictures/.

People often think that a silent PC equals massive price tag.  This is not true.  You can build a silent PC on a budget if you know what to buy.  I will give the breakdown of the components that can be silenced and the price difference.

Fan controller

This is an optional part, but I highly recommend getting one.  The Scythe “Kaze Master Ace” 4 fan controller which retails for $44.80 can be purchased for less than $40 CDN at many computer stores.  The controller can be seen at http://www.scythe-usa.com/product/acc/045/km02_detail.html.  silent 120mm fans spin at 1200 RPM’s, but I find that they are still noisy.  Therefore, I use the controller to reduce the RPM’s to 900-1000 RPM’s.  The computer is very silent.  A Gelid one fan speed controller for about $6 CDN can be seen at http://www.gelidsolutions.com/products/index.php?lid=1&cid=13&id=37&tab=5.

Power supply with case

Generic = $39(both)

Silent solution = $35(power supply)+50(case)

Apparently, it seems that a power supply with a 80mm fan is also quiet.  The problem is the efficiency.  The less efficient a power supply, the more noise it will make.  This makes sense.  Unused power turns into heat.  Therefore, the secret to a silent power supply is really one that is very efficient.  You can look around and if you find a cheaper power supply that is energy efficient, by all means get it.  The one used for this calculation costs $35.  I still prefer the bottom 120mm, but one will have to use their own judgment.

Antec sells silent cases which are specifically designed to minimize noise.  Antec’s Sonata family of cases can be seen at http://www.antec.com.

Intake and exhaust fans

Larger is better.  There are larger fans than 120mm, but the price gets much higher.  Furthermore, 120mm seems to be the most common sizes used for intake and exhaust.  1200 RPM’s are the most common speeds, but I find 900-1000 RPM’s to be both very silent and provide enough airflow.

It seems that an intake fan is not necessary.  Having only an exhaust fan can provide better cooling than having both an intake and an exhaust.

Small (80mm fans) = $5 each
Large (120mm fans) = $5 each

No fans = free       4 pack of CoolerMaster 120mm  silent fans = $17

CPU heatsink and fan

Generic = free                      Silent = $50

http://www.scythe-usa.com has various aftermarket computer parts.  They sell heatsinks that can hold any 120mm fan, and it is easy to replace the 120mm fan.  Furthermore, the prices are reasonable.  Therefore, this is a company that I often will buy parts from.

Video card (It seems that some motherboards with an  onboard video card are fanless.  Therefore, a fanless video card may not be necessary)

With the introduction of the Intel Sandy Bridge and the next generation of CPU’s called Intel’s Ivy Bridge that has a decent video card built-into the CPU, a large fan over the CPU/video card is a cheaper alternative.

Onboard = Free                        Silent = $40

Motherboard and RAM

As of Nov 8, 2009, motherboards and standard RAM do not have fans yet.  Some of the high end expensive ones do, but I am assuming that you are buying on a budget.

In the end, you will be spending about an extra $46+$17+$50+$40= $153 on a silent computer.  $113 if you are not going to buy a separate video card.  This computer is not designed for a power user, but a user who wants a quiet computer for surfing the Internet and/or working on documents.  There are other components that I did not mention, and there is a reason.  They cannot be silenced.  Therefore, buy these parts based on your needs.

I have an article written up with my current silent computer configuration.  I have every part mentioned here except for the case.  The article can be found here.  This page can also be found by going to http://asecurepc.com/wiki/doku.php?id=build_a_silent_computer

In conclusion, the secret to keeping a computer silent is actually not only larger fans, but also to keep the inside cool.  Since the computer case is a closed box, no air can get in or out.  I used to take off the side to keep the computer from getting too hot and noisy, but I wanted to find a better solution.  Therefore, intake and outtake fans are a must for any computer.  If the inside gets too hot, the fans will run faster to push more air around.  This defeats the whole purpose of getting larger fans.  My current computer is fairly quiet during the summer even with the case closed.  This is due from the constant airflow in and out.

As of November 1, 2009, I have bought a new silent computer.  It can be seen at http://aprivatebeach.com/blog/2009/11/custom-silent-pc-nov-2009/

Parts used and assumptions made in this article

As for my computer, I have tested various locations, and I have decided on the best setup for me.  This is a negative airflow setup.

Using a Scythe “Kama Stay” multi purpose solution, I have a 120mm fan blowing on both the Northbridge and the video card.  Furthermore, I have 1 exhaust fan at the back of the case.  There is also another exhaust fan at the front of the case.  I need to clean the computer every year, otherwise, the inside will become all black from the dust.

I have previously tried having a fan blowing towards the CPU as shown below, but decided to create a more negative air pressure computer.  Since the top 3 bays feels warm to the hand, I installed a fan to push the air towards the exhaust.

The Scythe “Kama Stay” multi purpose solution can be seen at http://www.scythe-usa.com/product/acc/071/sckst1000_detail.html.

2 thoughts on “Build a quiet(silent) PC Dec 2009”

  1. Many computers are quiet the way they are. Unfortunately, mine was noisy. If I had the parts, I could try various different configurations, but I don’t. Therefore, I go with what was written on other websites.
    If you don’t mind, what do you have in your computer? Fan size, number of fans and power supply.

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