Quiet PCs: the appliance of silence

Silence may well be golden but, unless you're a member of your local sensory deprivation society, it's also in short supply.

Background noise is an unfortunate fact of life but, short of recommending an earplug manufacturer, vnunet.com's sister publication Computeractive can't do much about it. Actually, that's not quite true; we can do something about one noisy thing that you have at home - your PC.

You've probably got an idea how much noise your PC makes but put an ear next to its case and you'll appreciate just what a racket you've been putting up with.

All unwanted noise is annoying but, if the thing that's making it is also the thing you're using to concentrate on work, it's a huge distraction. If the PC is in your living room acting as a DVD or CD player, its background din will detract from your movie or music enjoyment and, if your PC is in your bedroom, it'll keep you awake.

The good news is that this noise isn't necessary and silencing your PC is possible with a little effort and a little know-how. If you've read this far, you're obviously interested. Read on and we'll give you the rest.

Feeling hot, hot, hot

Modern processors run at high temperatures, anything from 40 to 70 Celsius, so a cooler is essential to stop them from burning out. All processor coolers use passive cooling in the form of a heat sink.

A heat sink is something that conducts heat away from an object in contact with it and dissipates it into the surrounding air more efficiently than the object itself.

Heat sinks are usually made from aluminium - it's cheap, conducts heat well and is easily machined - and are often made up of large numbers of spines or fins to increase surface area.

A heat sink isn't enough to cool a hot processor, though, since it can soon heat the surrounding air to a temperature close to that of the heat sink itself, which means that the heat won't dissipate.

So to help matters, most processor coolers also use active cooling in the shape of a fan to blow cool air through the heat sink.

Unfortunately, PC manufacturers like to shave costs wherever they can and a poor heat sink with a fast fan to compensate costs less than an effective heat sink and a slower, quieter fan. Listen inside any standard PC and you'll hear that most of the noise is made by the processor fan.

Air heated by the processor heat sink doesn't just disappear, it builds up inside the case. Obviously cool air is needed for effective cooling so most PCs also have a fan at the front of the case to suck in fresh air; some also have one at the back to suck hot air out.

Add in the fan on the power supply and possibly one each on the graphics card and motherboard and the amount of fan noise becomes appreciable.

With manufacturers concentrating solely on getting more performance from components, the inside of PCs are only going to get hotter and that means more cooling which, you guessed it, means more noise. So for a silent PC, we'll twist an aphorism and say that you need to cool smarter, not harder.

Hush now, what's that sound?

With all those fans inside, it's no surprise that most PCs sound like failed Frank Whittle experiments. Some motherboards can vary the speed of fans attached to them according to the ambient air temperature but, if yours doesn't, there are a couple of options available.

The simplest is to download SpeedFan. This is a free utility that lets you reduce the speed of your fans while keeping a watchful eye on the temperature. SpeedFan isn't terribly easy to use, and not all motherboards provide the information it needs, so if you can't use it, there is a plan B.

If you're confident enough to remove your PC case and unplug a couple of cables, a fan speed controller might solve your problem. Available from Chillblast, this £23 gizmo connects between your motherboard and up to two case fans.

A small dial lets you adjust the fans' revolutions per minute to a point where they don't make a noise but, once the speed is set, it's fixed. So if you find that your slow fans aren't cooling your case properly, you'll need to poke about inside your PC again to increase their speed.

Cool for cats

Slowing down the case fans is the simplest way to quieten your PC but, if you have a fast processor, most of the noise will come from its heat sink fan. Slowing this down isn't a great idea, since the cheap heat sink in a typical PC isn't likely to be efficient enough to compensate, and a hot heat sink equals a burnt-out processor.

The solution is to replace the processor cooler with something more efficient. The Noise Control Silverado from Chillblast (£45) uses an aluminium heat sink and has two fans mounted vertically above it.

The part that comes into contact with the processor is pure, polished silver for greater heat conductivity and the fans have four speed settings.

Quiet as it may be, the Silverado is still just a processor cooler. The Zalman CNP S6000-Cu from Quiet PC (£34) is, however, a work of art in its own right.

It has 56 copper fins that spread out at the top and are gripped tightly together at the base, which has been machined perfectly flat for contact with the processor.

The fins give a total surface area of approximately 0.3 square metres for cooling, which is between three and 10 times more than most heat sinks. A large fan sits above it which screws to the PC's expansion slots, and a speed controller controls its RPM.

Both can cool 1GHz processors in complete silence but, while the Zalman was a cinch to fit, it took a great deal of effort (and cursing) to get the very tight clip of the Silverado onto the processor socket.

Fight the power

A PC is only as quiet as its loudest component and, with both the processor and case fans silenced, you still won't have a quiet PC. The final piece in the PC pandemonium puzzle is the power supply and, thankfully, it's one that can be easily fixed.

The Q Technology Ultra-Quiet PSU from Quiet PC (£54) performs just like a standard 300W power supply but with one difference: it's silent. As well as running noiselessly, the fan speed is controlled thermally so if the PC is cool inside, the fan will run more slowly and reduce the noise made by the blades slicing through the air.

Replacing a power supply isn't a quick job but it isn't complicated either. Disconnecting and reconnecting the cables can take some time but it's a task well within the ability of most PC users.

The sound of silence

Fixing your fans will go a long way to quietening a PC but achieving silence needs a little bit more work. As a small project, we set out to build a PC that took noise control to the limit.

All PCs need active cooling because their interiors are heated by their components. If the heat could be removed by another method, the fans could spin very slowly, creating less noise.

Unfortunately, standard steel PC cases do a good job of trapping heat, but an aluminium one would conduct some of it away through the case itself. It's used for heat sinks, remember?

Aluminium cases cost more than steel ones but they look fantastic and are a fraction of the weight. Lian-Li produces a wide range of models and we opted for the anodised black PC-61 (£124 from Bosse Computers).

This has two three-speed fans at the front of the case, which run inaudibly at their slowest setting, and uses thumbscrews throughout for easy assembly.

Lian-Li reckons that an aluminium case will cut the interior temperature of a PC by at least 10 degrees Celsius, which is just what we need.

Since we wanted to build a powerful system, we used an AMD Athlon XP 1800+ processor, even though these run rather hot compared with their Intel equivalents. But even on their slowest, silent settings, the Zalman and Silverado coolers are more than able to keep the temperature down.

We settled on the cheaper Zalman, since it was easier to fit and came with a special tool that made attaching the sprung clip to the processor socket very simple.

Since we were building more or less from scratch, we picked a motherboard that used passive rather than active cooling, but heat sinks are available for motherboards that have a small fan on the chipset. MSI has a variety of passively cooled motherboards for all processors and we picked the rather natty red K7T Turbo2 (£80 from Dabs.com).

Our ATi Radeon 7500 graphics card is also passively cooled but again, heat sinks are available to replace fans on other cards. Hard disks are also inherently noisy but there are a couple of options for hushing them up.

The NoiseControl Hard Drive cage (£25 from Chillblast) suspends the hard disk between thick rubber bands, damping down all the vibration that would otherwise be transmitted through the PC chassis. Although it doesn't dampen any actual noise, it did prove more effective than the SilentDrive (£23 from Quiet PC).

This is a sound-insulated pod into which the hard disk fits, but we found that noise was still transmitted to the PC chassis through the pod's mounting brackets.

As a final touch, we used some MagicFleece adhesive damping mats (£40 for six from Chillblast). These adhesive-backed mats look a little like carpet tiles and use layered cork and fibre to cut down noise, so we fitted some to the inside of the large side panels on our case. With effort, however, it is possible to insulate almost every interior panel.

It's oh so quiet

The noise level of a quiet room is around 28 decibels (dB); a public library is around 40dB; a typical office 50dB. Anything below 33dB is considered 'quiet'; anything below 28dB is considered silent. So how did our DIY PC compare?

The room our PC was in measured 27dB during the day and the 1GHz Pentium III PC that used to be in there (we cannibalised it to build our quiet PC) raised the noise level to 40dB when it was switched on. Our new quiet PC, on the other hand, increased the noise level by just 1dB to 28dB.

A quick check on temperatures in the BIOS revealed the interior case temperature to be a reasonable 25 Celsius. The Pentium III PC was 40 Celsius. Our cooling is a success.

In subjective terms, our efforts have produced a PC that barely makes a whisper, and you have to listen to it closely to tell that it's even switched on.

If we'd stuck with the Pentium III processor from our old PC, our modifications would have cost £176 for the fan controller, Zalman cooler, power supply, drive cage and sound insulation.

The Pentium III runs cooler than an Athlon processor and, with our Zalman cooler, the extra cooling provided by the aluminium case is unnecessary.

For the sheer aesthetic improvement over the usual beige steel though, it's well worth the extra money.

CONTACTS

Aluminium PC cases:
Bosse Computers
www.bossecomputers.com

Processor coolers, hard disk dampers, sound insulation, fan controllers:
Chillblast
www.chillblast.co.uk

Processor coolers, quiet power supplies, hard disk insulators:
Quiet PC
www.quietpc.co.uk

Fan-less motherboards:
MSI
www.msi.com.tw
Dabs
www.dabs.com

Free fan control software:
SpeedFan
www.almico.com/speedfan

JARGON BUSTER

BIOS Basic Input Output System. Software built into all PCs to control the basic operation of devices such as the screen, hard disk and keyboard. When a PC is switched on, the BIOS kicks in automatically and looks for a drive (like the hard disk) from which the operating system proper can be launched.

Chipset Broadly speaking, any group of computer chips working together to perform certain functions. For example, a graphics card will have a number of chips - the chipset - designed to handle all graphics output.

Download The process of transferring files onto your PC directly from another computer. You might, for instance, download pictures and files from the internet.

Expansion slot A socket on a computer's motherboard designed to accommodate expansion cards.

Gigahertz (GHz) A measure of how fast the processor in your PC works.

Graphics card The part of a PC that displays the image you see on your computer's monitor. Some are more advanced than others, featuring connections for video recorders or other similar devices.

Motherboard The main circuit board inside any PC into which every other component connects to and communicates through.

Processor The chip that is the 'brain' of the computer. The faster the processor, the better the computer will perform.