Build Your Own

Home PC Computer System

PC computer cases used to be plain-Jane beige, but now come in many sleek styles and custom colors. However, when deciding on one for the home computer you're building, there are key considerations to be made other than the aesthetic appeal.

Chassis (Case) & Power Supply

The case was probably the most overlooked part of the whole computer at one stage. Most cases were beige, and since most components drew far less power than similar components do now, power supplies were never talked about. Recently, however, cases have become considerably more attractive, and people spend a sizable amount of their upgrade budgets on lights and glow-in-the-dark cables. Cases now come in a plethora of styles and colours to suit anyone's taste.

People are spending more money on cases now than they ever have before. If you are only building an office computer, the style of case will be of little concern to you, so you might only want a inexpensive ATX case (ATX is the specification which makes them the same size, so you can put the same parts inside), and an inexpensive power supply, since you won't be running high-end processors or high-end graphic cards. Keep in mind not to buy a power supply with a sleeve bearing fan, as these are of considerably lower quality. As a guide, you will not want a power supply with a rating of less than 300 watts, as you may likely not be able to power all the parts in your computer with a power supply with a lower rating. Most case-power supply bundles are adequate, but tend to be of a lower quality than power supplies that are sold separately from cases.

For a quiet system, you may want to choose a fanless power supply -- more expensive but well worth it if noise is a concern.

For cases and power supply there are 5 things to consider.

Formfactor

For general use, the ATX formfactor is recommended because it allows your computer to be easily expanded, and is the most common standard formfactor for computers.

• ATX In this form factor the motherboard is vertical for more space and more efficient cooling.
• Micro ATX is smaller than vanilla ATX, but at the cost of fewer expansion slots. Flex ATX is even smaller than Micro ATX, but only allows 2 expansion slots.
• WTX is intended for workstations and servers.
• BTX is another formfactor designed for more efficient cooling. o PicoBTX 8"x10.5" o 'MicroBTX up to 10.4"x10.5" o BTX up to 12.8"x10.5"
• Mini-ITX is even smaller than BTX, at 6.75" square.
• NLX

Many OEM computers use non-standard formfactors. Be sure to choose a motherboard compatible with your case's formfactor.

Number of Storage Drive Spaces

Internal hard drives/floppy drives (which go in the small 3.5" bays) and internal DVD drives (which go in the large 5.25" bays) take up space in the case, so make sure you consider how many drives you have. It is usually a good idea to calculate the number of drive spaces needed using your motherboard requirements as a baseline minimum.

• Number of IDE x2
• Number of FDD x2
• Number of SATA
• Number of SCSI2 (estimated)

e.g. For a motherboard with one FDD, one IDE, 4 SATA no SCSI. It is often best to choose one with at least 8 slots.

4 BIG + 4 SMALL = 4 optical drives + 3 hard drives + 1 floppy drive

This is the mid-tower configuration. For smaller computers with less storage drives, like 1 hard drive and 2 optical drives, get a mini-tower (2 BIG + 2 SMALL) because it saves space.

Note that it's possible to buy adaptors to fit items that go in small bays (usually hard drives) into large bays. It is however not possible to do the reverse.

Power Rating

A too small power number doesn't run your high power devices (like optical, CPU and Graphics Cards). For certain graphics cards (especially high end ones with dual expansion slots), a recommendation of 450W is required. In general, if your motherboard has a 24 pin power connector, choose one which is at least 350W as the 4 extra pins are for high power applications. Also, for SLI gaming (dual video cards) you would want a PSU (Power Supply Unit) with dual 12 volt rails rated together for at least 30 amps.

There are several calculators that try to tell you the most adequate PSU for your system. Some of them:

• http://web.aanet.com.au/SnooP/psucalc.php
• http://www.extreme.outervision.com/psucalculator.jsp

Choose an efficent PSU. Efficient PSU runs cool and quiet and thus do not cause much noise (important if you plan to sleep in the same room with it or using it as a media center PC)

More informations about this theme can be found in Silent PC Review, OCAU Wiki, among others.

Note: Intel Pentium 4/D/EE have high power requirements, a 300W PSU is recommended.

Fan

Some cases have case fans. Make sure to choose one which matches your CPU interface on the motherboard. The best option is to purchase a 4-pin Molex connector fan as some motherboards do not have three pin fan ports. Although most motherboards fit most cases, it is the position of the case fan that affects speed and stability of the system. A good case has the fan aimed directly at the CPU for best results.

Aim to choose fans which are quiet. Usually larger fans run slower and produce less noise (and thus more efficient).

Aesthetics and Power

If you plan on building a high end gaming PC, you might want a case that looks good, and a much more potent power supply. For the more aesthetically inclined, there are countless companies who make designer cases that will suit many personal preferences. A power supply with more than 400 watts is usually more than is required by most people, and will allow you to power mid-range graphics cards, cooling systems, and aesthetic enhancements such as cold cathode lights, cooling equipment, and other such things. However, high-end graphics cards consume a lot of power so consider 600+ watts for a single graphics card and 700+ watts if you plan on using SLI or CrossFire. For example, nVidia recommends a minimum of 400 watts for a single 7900GTX and 500 watts for two 7900GTX video cards in SLI configuration. A little research before buying can help you find appropriate power requirements.

In all cases you should try to check reviews from a computer hardware site before you decide to purchase a power supply; quality can vary greatly and wattage output is frequently overstated. Quality power is also usually more efficient, so it will produce less heat and its fans can run at lower, quieter speeds. Manufacturers sometimes try to make passive, or fanless, power supplies, but in most cases they will end up running dangerously hot, and so are only suitable if you plan to add your own cooling solution.

Antec SmartPower 2.0 SP-450 450-Watt Power Supply Unit