Contents
1.Cooling and noise
- 1.1 Fan regulation
- 1.2 Harddisk
2. What if I already purchased the HTPC and I dont want to touch the hardware?
- 2.1. Fan-noise
- 2.2. CD/DVD-noise
- 2.3. Hard-drive noise
1. Cooling and noise
Nobody wants their shiny new HTPC to sound like a loud vacuum cleaner. But often, that is what happens when you assemble a typical system from regular components. Manufacturers often focus more on the "hardcore overclocker/gamer crowd" than living-room computers. The consequence is that we will have to do some googling (
http://www.google.com ) and educated guesses to minimize noise while still keeping a stable and fast HTPC.
The easiest solution is buying a pre-assembled system with all the tweaks in place, but whats the fun of that? =) You can also purchase low-performance hardware such as
www.mini-itx.com systems that may get the job done with less power (=heat) developed. You may even get passive systems (= no fans!). The challenge is building a near-silent computer yourself, using regular hardware AND keeping aestetics, performance and stability.
Usually, high performance means more electric power, and more electric power means more heat. In most systems more heat means more noise. We dont want that...There are ways to:
1)Remove heat while generating as little noise as possible
2)Only generate heat when it is really needed (dynamic systems)
3)Only remove heat when it is really needed
The conclusion of 1) to 3) is that we want a system that runs at a constant TEMPERATURE, not one that runs at a constant NOISE level. This fits as most computers perform their maximum only 1% of the time, while the cooling/noise is at 100% all of the time...
1.1 Fan regulation
In comes temperature/termostat controlled fans, large radiators, large fans. If you can:
1)remove the heat from each component without making excessive noise
2)remove that heat from the case and into the living room without making excessive noise
then you have come a long way. This can be done by using large CPU coolers with heatpipes and/or Cupper ribs, large graphics coolers etc. Then you would want to use large, slow-moving system fans or PSU fans that will suck enough air while making as little noise as possible.
Such a system can usually be controlled by
almico so that fan-speeds ramp up when relevant temperatures ramp up. In my system, the system fans will stop after windows has booted. Only when the temperature gets high enough will they slowly ramp up in speed.
1.2 Harddisk
Harddisk
How much, how fast, what type?
There can never be enough hd space. If you are going to tape a lot of shows or use the HTPC as a server, you will probably want to have more than one large drive. A pure windows/MP installation in itself takes almost no space, so if you are primarily sharing media files from another computer, or using MP for live viewing of tv/radio etc, you may get by on a small drive.
7200rpm drives are generally faster and noisier than older 5400rpm disks. Nowadays, most disks are 7200 anyways. Samsung P80/P120 series have a very good reputation for low noise and low temperature. The are typically not available at the largest sizes (max 300GB currently).
The typical HTPC may benefit less from really fast hard drives than a typical office computer.
You may find tests of hds and hd silencing remedies (including DIY) here:
http://www.silentpcreview.com/section14.html
Discussions of the same topics can be found here:
http://forums.silentpcreview.com/viewforum.php?f=7
A tool for managing disk noise :
http://www.rt-sw.de/en/freeware/freeware.html
2. What if I already purchased the HTPC and I dont want to touch the hardware?
This is more difficult. Some options:
TIPS FOR DECREASING PC NOISE WITHOUT TOUCHING A SCREW-DRIVER
You have bought a new, fast PC/HTPC for listening to music, recording movies etc. Onceyou have set it up, the satisfaction is spoiled once you find that it is whining or buzzing from small, cheap fans. You may consider returning it, swapping some components, perhaps you regret about not asking for help on a forum like this before making the purchase
Two primary sources to noise are cooling-fans and CD/DVD-drives. The problem is that the better their primary function (good cooling, fast CD-reading), the more noiseyou will usually get. A powerful fan makes more noise than a less powerful fan (although some make a lot of noise while still cooling poorly). A 48x cd-rom is more noisy than an 8x one. But we want "100% performance" AND "low-noise". One approach to this is striving for a PC that generates noise only when needed - ie when you are calculating PI with a million decimals, or ripping you cd-collection, not otherwise.
The cool thing is that a few enhancements can be made in software only, therefore I will not discuss noise-absorbing mats, expensive coolers, hd-decoupling rubber-bands etc in this section.
2.1 Fan noise
Speedfan is a small utility that lets you control fan-speed automatically controled b built-in hardware sensors that all modern CPUs, motherboards, hard-drives etc feature. This helps with our goal (remember - noiseonly when calculating PI)
The application runs as a background task and can start automatically at windows start. If desired, you can set it up to default all fans to maximum speed upon application exit.
Image 1:
Startup screen. Check "Automatic fan speed". You will get a oveviw of all tempertues, fan-rpm and fan-power in percent.
Image 2:
The "charts" fan will give you hisorical reading of one or more temps, speeds and voltages. Notice how the hd temp (red) is constant, while the cpu tp (grey and green) changes.
Press "configure".
Image 3:
We are now at the temp fan. Your image may look slightly different depending on your cpu. To rename eg "Temp1" to the more readable "cpu", click it and press f2
I have opened "CPU". We can see that it is set to 50 degrees C as "desired" temperature, and warning at 65 degrees. Of course you can change this. We are also seeing that the "CPU fan" is checked. This means that the cpu temp will affect the cpu fan speed. We could also make it affect the system fan - depending on the airflow of our cabinet.
Image 4:
I have chosen the "speeds" fan, and "cpu fan". It is setup to allow regulating, and the minimum value is 0%. The maximum value is 100% (12V in a usual circuit, I guess). Some fans my need a certain voltage to start at all. By setting a mnimum value here, you may be able to remove any oscillation occuring if the feedback-loop is behaving poorly.
2.2 CD/DVD-noise
If your CD/DVD is noisy, there are applications that spin-down their speed, and therefore the noise. For reading both CD and DVD playback (not ripping), 1x speed should be enough.
Examples of such applications:
http://www.slysoft.com/en/anydvd.html
http://ww2.nero.com/enu/index.html
Using AnyDVD, you can select different modi for music-CD/movie-DVD and data disks.
It will also strip user-restrictions and FBI-crap.
2.3 Hardddrive noise
http://www.silentpcreview.com/article29-page1.html
Harddrives can also be noisy, you will especially notice this once you have turned down the fan noise. A rule in silent computing says that any improvement in noise just reveals other noise sources that was inaudible before
The only possibility for decreasing hd noise in software is changing its spindown settings, and enabling "AAM" at the expense of some speed.
http://www.hitachigst.com/hdd/support/download.htm
More background info
To get some more insight, I recommend a website with a very relevant forum:
http://www.silentpcreview.com/
These guys are testing hard-drives, cpu-coolers, fans/fan-controllers etc, and they have been doing so for many years. I think that their testing methology with calibrated "lab" measurements, mp3 sample-recordings and subjective impressions is as good as any source. Most enthusiasts with an interest for low/no-noise PCs use this site as a reference.
Hope this was of any use.
Knut
