Apart from the major components, you need several other accessories to complete your system. These are the small parts that can make the assembly process a pleasure or a chore.

If you are purchasing your system components from mail-order sources, you should make a complete list of all the parts you need, right down to the last cable and screw, and be sure you have everything before you begin the assembly process. It is excruciating to have to wait several days with a half-assembled system for the delivery of a forgotten part.

Heatsinks/Cooling Fans

Most of today's faster processors produce a lot of heat, and this heat has to be dissipated so your system doesn't operate intermittently or even fail completely. Heatsinks are available in two main types: passive and active. Passive heatsinks are simply finned chunks of metal (usually aluminum) that are clipped or glued to the top of the processor.

They act as a radiator and, in effect, give the processor more surface area to dissipate the heat. Active heatsinks are required by many processors today because of their higher capacity and smaller space requirements. Often you have no control over which heatsink you use because it comes already attached to the processor.

If you have to attach it yourself, you should use a thermal transfer grease or sticky tape to fill any air gaps between the heatsink and the processor. This allows for maximum heat transfer and the best efficiency. An active heatsink includes a built-in fan.

These can offer greater cooling capacity than the passive types, and some processors—especially "boxed" processors from Intel and AMD—are sold with the heatsink and fan included. OEM processors don't include a heatsink from the processor manufacturer, but most vendors who sell them add an aftermarket heatsink and fan to the package; often, aftermarket heatsinks and fans provide significantly better cooling than those shipped with boxed processors.

Thus, an OEM processor is a better candidate for overclocking. Note that all modern heatsinks require a thermal interface material (usually grease or paste) be applied to the base of the heatsink before installation. Another consideration for cooling is with the case.

The fan in the power supply and optionally one on the CPU heatsink often are not enough for a modern high-performance system. I recommend you get a case that includes at least one additional cooling fan. This is typically mounted in the front of the chassis, taking air in from the front and directing it over the motherboard; it often is hidden behind the card support slots used for full-length expansion cards.

Some cases include extra fans near the drive bays for cooling the drives as well. If you are upgrading an existing system, several companies make fan assemblies that insert into a drive bay for additional cooling. They take the place of a 5 1/4'' drive and take air in through the front bezel, directing it back into the case.

Bay-mounted fans are an especially good idea if you are using the 10,000rpm or faster SCSI drives on the market because they run extremely hot. There are even fan assemblies mounted on cards that blow air out the rear of the case. Keep in mind that it is best to keep the interior of the PC below 100°F; anything over 110° dramatically reduces component life and leads to stability problems.

Cables

PC systems need many different cables to hook up everything. These can include power cables or adapters, disk drive cables, internal or external CD-ROM cables, and many others. Frequently, the motherboard includes the cables for any of the internal ports, such as floppy or hard drives.

Other external devices you purchase come with included cables, but in some cases, they aren't supplied. The Vendor List on the DVD contains contact information for several cable and small parts suppliers that can get you the cables or other parts you need to complete your system.

Another advantage of the ATX motherboard form factor is that these boards feature externally accessible I/O connectors directly mounted to the rear of the board. This eliminates the rat's nest of cables found in the older Baby-AT form factor systems and also makes the ATX system a little cheaper and more reliable.

If you build your system using all OEM (what the industry calls white box) components, be aware that these sometimes don't include the accessories, such as cables and additional documentation, that you would get with a boxed-retail version of the same component.

Hardware

You might need screws, standoffs, mounting rails (if your case requires them), and other miscellaneous hardware to assemble your system. Most of these parts are included with the case or your other system components. This is especially true of any card or disk drive brackets or screws.

When you purchase a component such as a hard drive, some vendors offer you the option of purchasing the bare drive or a kit containing the required cables and mounting hardware for the device. Most of the time bare drives don't include any additional hardware, but you might not need it anyway if the mounting hardware comes with your case.

Even so, spending the few additional dollars for the complete drive kit is rarely a waste of money. Even if you're left with some extra bits and pieces after assembling your system, they will probably come in handy someday. In situations in which you need other hardware not included with your system components, you can consult the Vendor List for suppliers of small parts and hardware necessary to get your system operational.