0 Power Supply (PSU)

An introduction to Power Supplies 

The power supply is probably best described as being the heart of the computer. It provides all of the other components in the computer with… well, power. It‟s responsible for converting AC electricity from the mains into the more usable, lower power DC before distributing it to the other components.

The most common type of power supply is the ATX power supply, which uses standardised connectors compatible with the vast majority of motherboards of any size. PSUs come in two varieties: Modular and Non-Modular. I‟ll be talking about both  later.

Inside the Enermax Modu87+ 900W – One of the best PSUs you can buy!

0 The Case (Noise Insulation)

Noise Insulation

The computer case itself also helps to keep your computer quiet. Computer parts can make a surprising amount of noise (the processor’s heatsink fan and hard drives are the main culprits; discrete graphics cards can be very loud, too), and the case can be instrumental in making sure most of it doesn‟t reach your ears.

Unfortunately, while fairly good at blocking direct noise, cases can sometimes be susceptible to absorbing vibrations from other components, blocking the high pitched noises but generating its own low hum.

The first (and most common) noise reduction technique involves isolating the case from any vibrating parts using rubber or silicon. This can be something as simple as putting a thin layer of insulation between the component and the case or as elaborate as suspending it in its own bracket, using insulation at multiple points.

Some cases sometimes use noise reduction panels fixed to the chassis like the Cooler Master Sileo 500, pictured here. This foam- like material “absorbs” sound from inside the case, making things a lot quieter. These cases aren‟t without their downsides, though. For noise insulation to work properly, you need to have the case as sealed as possible, which can seriously affect thermal performance if there isn‟t sufficient airflow from the fans. It‟s very difficult to keep a computer extremely cool and quiet. It‟s usually one or the other without getting water cooling involved, which we won‟t be covering in this guide.

Some cases take particularly novel approaches to noise reduction. Some examples that come to mind are the  Fractal Design Define R2, with its internals coated in bitumen for noise reduction, and the  Antec P180 series, which has side panels made with three layers; a layer of plastic sandwiched between two layers of aluminium, acting a bit like double glazed windows for sound. Again, www.silentpcreview.com has a lot of information on this subject – after all, that‟s why it was originally started!

0 The Case (Airflow)

Airflow

Airflow is possibly the most important job of a good case. Components can get very hot, and good airflow is needed to get that heat away from the components. Without sufficient cooling, they can become less reliable over time and degrade faster.

Many cases that you buy yourself may come with only one or two fans but have mounting holes for more, allowing you to add extra ones. The most common fan size is

140mm, followed closely by 120mm. 80mm fans are also relatively common, but usually on smaller computers. Finally, you can also get 92mm, 60mm and 40mm fans, but these aren‟t used as often.

There are three main airflow models, each having its advantages and disadvantages:

1.  Negative Pressure – when exhaust exceeds intake. The idea behind this is that a negative pressure gradient is formed, sucking all the hot air out of the case.

2.  Equalised Airflow – when you have equal air intake and exhaust. This is the most common, and works by creating a wind tunnel.

3.  Positive Pressure – when, you guessed it, intake exceeds exhaust. The idea behind this is that new air is constantly fed in, pushing hot air out of the case and replacing it with cool air.

The biggest problem with getting a good airflow is the amount of noise generated by the fans, particularly by many small fans. There are usually two solutions to reducing noise:

1.  Isolate the fans from the case to prevent noise-creating vibrations to be passed to the main chassis. This does not make the fan itself quieter, but can significantly reduce overall noise. Many higher end cases provide rubber grommets for the fans in their cases for this purpose.

2.  Buy better fans – These tend to use ball bearings or fluid bearings rather than the cheaper sleeve bearings. They have the extra bonus of lasting a lot longer, too.

The other alternative is to buy a case with one or more larger fans. These are great because they can generate the same CFM (cubic feet per minute of air, the standard measurement for air throughput for fans) while spinning with fewer RPM (revolutions per minute) and thus creating less noise.

When you go to buy fans, it‟s much better to get the fans from a well-known brand. You‟ll pay a bit of a premium, but it‟s worth it for the lower noise and longer fan life. Some good brands to look out for are Akasa, Antec, Noctua, Scythe, and Zalman. There are some other good brands out there, but these are the ones to get.

If you want to keep your computer as cool as possible, there are a few companies who will be happy to sell you cases designed for airflow. Examples include Cooler Master’s HAF line (HAF stands for high air flow, funnily enough) or Antec’s Gaming Series (including the 300, 902 and 1200 cases).

0 The Case (Layout)

The most obvious part of the computer is often overlooked. As the skeleton of the computer, many people think of it as nothing more than something to bolt the components to keep them protected. The case is also instrumental in providing airflow and noise insulation.

Layout

The layout of the case is quite important, although largely standardised. Until relatively recently, nearly all cases had identical layouts to that in the picture below:

Indeed, most budget cases still use this design, and for good reason – it‟s a conventional, solid design which works well for a basic computer. However, in the mid- range and high end market a few changes are becoming commonplace.

For example, you may begin to see the power supply being placed at the bottom of the case, below the motherboard instead of above it. This is a sensible idea, as it lowers the centre of gravity significantly. Another possible perk is removable hard drive cages, sometimes turned sideways (in larger cases) so that the hard drives are facing you as you remove the side panel. This gives you easier access to your hard drives as well as providing more space for longer graphics cards.

There are also some cases that throw convention out the window to great effect. Examples include the Silverstone Fortress and the Thermaltake Level 10 cases. They provide amazing layouts, although they do so at a great price premium.