Creating a custom PC is much easier than trying to guess which computer maker offers the right combination of features to satisfy your needs. Putting a system together yourself is pretty straightforward, and the job should take less than a single afternoon so long as you have a number of key ingredients.
As with cooking a meal, preparation is crucial. The most important decision you'll make for your custom PC is which motherboard to buy. Motherboard prices and specifications vary tremendously. And this isn't a choice that you can make in a vacuum, either, since it has an impact on almost every aspect of the system, from the CPU to the storage.
The Big Picture
What factors are most important when comparing motherboards? The processor? The chip set? Storage? Find out how these and other features will affect your system's performance. more
The Specs Explained
Is the fastest processor always the best choice? What type of memory should you look for? We explain which specs are most important, and why. more
Motherboard Shopping Tips
You'll want to consider the price, performance, and priority of several features before you look for a new motherboard. Our tips help you find the best value. more
The Big Picture
In many ways, the motherboard is the heart of the modern computer system, as it affects almost every other component. Choosing a motherboard is a fairly complicated task since you have seven to nine different factors to consider, of varying importance.
Take some time to think about how you'll use your system. Someone with a power meter that requires a serial port will care a lot more about the peripheral features than the average user will, while the hard-core gamer will probably focus on the GPU, CPU, and chip set while ignoring peripherals and form-factor issues.
CPU: The CPU, commonly referred to as the brains of a PC, is one of the key components (if not the key component) of a modern system. You have several mainstream options for your CPU. Intel currently has the highest-performing processor lineup, with the Core 2 Duo and the Core 2 Quad (which use the LGA775 socket). As the names imply, the Core 2 Duo is a dual-core CPU, while the Core 2 Quad is a four-core processor. AMD uses the AM2 and AM2+ socket and offers the Phenom (quad- or triple-core) and Athlon 64 (dual-core) CPUs. AMD's products are solid, but they generally provide lower performance. A lesser-known third player, Via Technologies, produces the low-power C7 processor; the C7 is a much less common option since it offers dramatically less performance than mainstream processors from Intel or AMD do.
Chip set: If the CPU is the brains of the PC, then the chip set is the spinal cord, responsible for tying together all of the different devices in the computer, and moving data among them. The chip set determines which CPUs, memory, and other devices can be used, and it can strongly influence performance.
The chip set is the single most important component of a motherboard. Since motherboards using the same chip set will usually have identical performance (barring serious design mistakes), they're differentiated by other features, such as the expansion slots, storage options, and other discrete chips that may be included.
Chip sets typically employ two different chips referred to as the northbridge and southbridge. Generally speaking, the northbridge is responsible for dealing with high-performance devices, while less-sensitive devices tend to cluster around the southbridge.
The northbridge traditionally includes the memory controller, plus integrated graphics or an interface for discrete graphics. (Note that AMD has the memory controller integrated into the CPU, rather than the chip set.) The southbridge includes networking, storage, audio, general peripherals, and other devices. The image here shows an example, the Intel X48 chip set with partitioning between the northbridge (or MCH) and southbridge (or ICH).
The major options for chip sets consist of Intel, AMD, and nVidia, though SiS and Via have alternatives.
Memory: Selecting memory for your PC is usually a simple decision: You just pick a reliable brand that's as cheap as possible (unless you like overclocking, but that's a whole different story). Every so often, however, memory types undergo a transition--and one happens to be going on right now. Most chip sets use DDR2 memory at up to 800 MHz (PC2 6400), but newer chip sets from Intel may also use DDR3. DDR3 offers more bandwidth (1066 to 1600 MHz), consumes less power, and will be mainstream in a year, but for the moment it is more expensive. DDR3 is more likely to be useful for later upgrades, but it will carry a price premium until sometime in 2009.
Telling a DDR3 board from a DDR2 board without the manual or box isn't particularly easy, since both slots use 240 pins. The difference is that the key (a small gap between the pins) is closer to the center of the DIMM (the memory module) for DDR2, while it is closer to the edge of the DDR3 DIMM. Remember: If the memory module doesn't fit into the slot, don't force it!
Graphics hardware: The graphics hardware (the graphics processing unit, or the GPU) is the third-most-important component of a system, right after the CPU and chip set. The main considerations for graphics are cost, performance, and upgradability.
The lowest-cost option is a chip set with integrated graphics. Integrated graphics processors (IGP in industry parlance) are intended for basic 2D and 3D functionality and often use system memory instead of dedicated graphics memory. All of the major vendors (AMD, Intel, nVidia, and VIA) offer integrated graphics with some chip sets. An IGP is a fine choice for users interested in a little multimedia, office work, and other lighter workloads.
Integrated graphics will work fine for about 60 percent of the world, but the technology almost always lacks the performance necessary for gaming. For users who want to play on their PC, the next step up is a motherboard with a single PCI Express x16 slot, which accommodates a discrete graphics card from ATI/AMD or nVidia.
PCI Express comes in two flavors, Gen 1 and Gen 2. The difference is that Gen 2 PCI Express slots run at 5 GHz, twice the speed of the previous generation. That distinction doesn't particularly matter for current GPUs (or most other peripherals), but it will be an issue for upgrading in the future. For a motherboard that you expect to outlast the GPU you pair it with, springing for a faster PCI-E slot makes the most sense.
If price is no object and maximum gaming performance is your goal, your selection is a bit different. True multi-GPU support is a very high-end feature and is priced accordingly. The only options for multiple GPUs are SLI (for nVidia cards) or CrossFire (for ATI cards). Given that nVidia is the clear performance leader, SLI is the superior choice for now; note, though, that SLI works only with nVidia chip sets and Intel's Skulltrail motherboard.
A separate but related concern is the graphics interface. You have three major alternatives: VGA, DVI, and HDMI. VGA is the traditional 15-pin analog monitor connector, designed for CRT displays. DVI is a digital connector specifically intended for use with LCD monitors, and HDMI is a variant of DVI with the DRM (digital rights management) technology required to play Blu-ray and other high-definition media.