Building a Silent Air Cooled System

Cooling/CPU Cooling by jmke @ 2005-03-11

Tired of those whining fans, want some peace and quiet when starting your PC? Read on to find out how you silence your system without turning it into a small oven.

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Intro & Specs

Madshrimps (c)


The purpose of this article is not to sell products or promote 3rd party retail solutions. We are simply showing products which are available in stores now which help you on your way to a silent system. If you are not afraid to mess around inside your PC then you will find plenty do-it-yourself methods on reducing noise. We will add them to each section to complete this article. They can be found at end of each section in YELLOW text

One of the most thriving segments of the hardware industry which has blossomed is without doubt silent computing. Almost any respectable manufacturer which deals with PC cooling has a product geared to those who can not stand noise.

While Dell, HP, Siemens and others have the advantage of incorporating their in-house designed cooling system with their desktop solutions, those who decide to buy a 3rd party PC (or assembly it themselves) must deal with components which are build for maximum compatibility. This often translates in louder then necessary systems due to the case, vga and CPU fans running at high speeds to keep things cool inside.

Today we take a closer look at how we can reduce the annoying noise from all those whirring fans and spinning hard drives. We start of with a relative small mid-tower case (with the included PSU) which features a pair of case fans, a stock CPU cooling and has everything screwed in tight.

The Noisemaker:

Case: Antec Lanboy
Case fans: 2x80mm (front: 2200rpm / back: 1800rpm)
PSU: Antec TruePower 350W
CPU: A64 3200+
CPU Cooling: Stock A64 heatsink
Motherboard/Memory: DFI NF3 Lanparty / Mushkin PC3200 LVL2 V2
Videocard: Chaintech FX5900XT
Hard drive: Maxtor DiamondMax 120GB PATA
Fancontroller: Coolermaster Aerogate II

For measuring noise the assembled system is placed in a room which measures a maximum sound level of 30dBA. The dBA is placed 60cm away from the front of the case.

Powering up the system gives us our first dBA reading: 39.1dBA

The system can be heard very well throughout the room, standing outside you can still faintly hear the spinning fans, with the door closed! So it's safe to say that this system is very noisy. Opening up the case it becomes apparent that most noise comes from the VGA cooler (the Chaintech cooler IS very noisy when compared to the stock FX5900XT cooling) and also the twin 80mm fan Antec PSU is causing some air turbulence.

We could simply power off all the fans inside the system and hope for the best, but PC components are quite susceptible to heat so we will be monitoring temperatures of different critical parts:

  • CPU (through Speedfan – reading from the DIE temp)
  • System (this is actually the Southbridge temp of the motherboard – through Speedfan)
  • PWM (the power circuit on the motherboard near the CPU socket – through
  • HDD (onboard temp read through Speedfan (SMART))
  • RAM (CM Aerogate II sensor between chips and heatspreader)
  • VGA (onboard GPU DIE temp read through Speedfan)
  • Top Case (CM Aerogate II sensor placed 10cm near top of case)
  • Bottom Case (CM Aerogate II sensor placed 5cm near bottom of case)

    With the system running at 39.1dBA we measure the following temperatures from the different components (in °C). Room temp during all tests was kept at 22°C

    System was loaded with K7 CPU Burn and 3DMark2001SE in loop until a stable temperature was measured for all components

    CPU: 57
    System: 34
    PWM: 46
    HDD: 29
    RAM: 38
    VGA: 57.5
    Top: 33
    Bottom: 31

    Let's see how we can improve things ->
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    Comment from petervandamned @ 2005/03/11
    nice one !
    Good review, Good subject
    Comment from Sidney @ 2005/03/11
    What I've gathered after reading the article:

    1) Case exhaust is vital.
    2)There are other heat generating components in a PC other than CPU and Graphic card we commonly talk about.
    3) Good CPU cooling is only part of the equation.

    Using sound meter is the best for sound evaluation; because some people just couldn't hear much of anything
    Comment from BugMeNot @ 2005/03/12
    You should probably have made a temperature target for each component.
    Obviously a lower temp is always better (unless you are keeping your coffee warm on your case), but if the CPU can live forever at 70 degrees it wouldn't matter what temp you got as long as you didn't go over that max temp.
    That said bearings would be the only thing that would be hard to nail down. I would suggest putting in a buffer temp into the bios to save the cpu.
    The best thing would be to have a PSU that keeps running even when the mobo powers down.
    Also, BTX should solve many cooling problems by using less fans.
    Comment from Sidney @ 2005/03/12
    Also, BTX should solve many cooling problems by using less fans.
    Let's "hope" so.

    BTX is focusing on CPU cooling from front inlet via duct work. I have not seen HDD cooling solutions in BTX. CPU will only be made cooler not hotter would be the better solution.
    Comment from Gamer @ 2005/03/12
    good work there.
    Comment from SuAside @ 2005/03/12

    wtf is upwith the NSYNC pics? finally showing your true nature jmke? ^^
    Comment from jmke @ 2005/03/12
    actually I added it to please you