Build Your Own High-Def PC

Motherboard, Processor, RAM, and Video Card

Lay a foundation for premium performance by selecting a great motherboard and CPU; then complement those components with fast memory and a high-def graphics card.

Motherboard
First, be sure to pick a motherboard that works with the previous parts: ATX versus MicroATX for the case and the right socket for your processor. The video card should work with any new motherboard's PCI Express slot, but get one with a like-brand on-board video chip set for best compatibility. (Or avoid on-board video entirely.) Skip a dedicated sound card by picking a motherboard with a surround-sound chip set and output plugs to match your receiver. The standard assortment of PC ports should be fine, but get gigabit ethernet for high-speed, wired video transfers over a home network. I picked the ASUS M3A32-MVP for compatibility with all of the previous components and for its silent heat-pipe design that provides extra cooling.

For PC World reviews of top motherboards, see our Top 10 chart.

Processor
Quad-core processors are going mainstream, but they draw a lot of power and generate excessive heat. Certain video editing programs take great advantage of the four cores, but we're aiming for a lower target. You could still build a good system with an Intel Core 2 Quad Q6600 or other similar chip--gamers take note--but I decided to go with something less powerful and a lot cooler. The AMD Athlon X2 BE 2400 works well for home theaters because its peak draw of 45 watts helps keep the fans quiet. This CPU's 2.3-GHz speed and dual-core architecture provide enough muscle for general media tasks, but a dedicated HD video decoder on the graphics card will add more power. Whether you go with an Intel CPU or one from AMD, you'll definitely want a dual-core processor to handle the system's multimedia tasks. 

You can install the processor simply by lifting the socket arm, carefully setting the chip in place, and lowering the lever--no pressure is needed.

CPU Cooler 
Your CPU should come with its own heat sink and fan, but those bundled components may well generate too much noise for an entertainment PC. Give them a try if you can, but don't hesitate to consider a replacement. While you can buy liquid cooling components that are completely silent, we're skipping that route because of the maintenance required, not to mention leaks. Instead, opt for a quiet, variable-speed fan attached to a heat sink. And double-check the specific model for processor and case compatibility. The Zalman CNPS9500 CPU cooler fits with my components and case, and it runs quietly when turned down.

When installing your own CPU cooler, be sure to apply an even, paper-thin layer of thermal paste over the processor's surface, and set the cooler in place. Try not to let the cooler slide back and forth over the CPU while seating it.

RAM
Current motherboards can support a variety of memory chips, but make sure that the exact type you select works with yours. Don't bother with the absolute fastest DDR3 RAM. Instead, spend your money on quantity: 4GB will be ample for Windows Vista or Windows XP Media Center. (And unfortunately, your particular OS and hardware configuration might not quite recognize all of it.) Also, go for a pair of the same 2GB DIMMs. Many current motherboards take advantage of dual-channel architecture so that each DIMM can access the memory controller. The middle-weight Crucial 2x2GB DDR2 PC2-5300 DIMMs strike a solid balance between price and performance.

Handle the RAM--and any other components, for that matter--only by its edges, and firmly push it straight into place rather than at an angle.

Video Card
The graphics card is one of the most critical components in our setup, since it's going to take over much of the HD playback from the processor. And in just the past several months, these cards have made a giant leap forward in quality while prices have dropped.

You don't necessarily need an ultra-high-end option: Those generate excessive heat. Instead, just make sure the card decodes Blu-ray Disc movies in addition to your own recorded shows. HDCP compliance--which decrypts the digitally protected video signal--is critical, but fortunately, it's also typical these days. The Asus EN8600 GT with HDMI is one good option, fulfilling these needs easily. At press time, nVidia was also readying its GeForce 8200 chip set for motherboards, bypassing the need for a dedicated HD graphics card. For my system, however, I picked the ATI Radeon HD 3450 video card, because it meets my other needs and doesn't require a fan for cooling. Unlike the Asus, this card lacks an HDMI port, but it works well with any DVI-equipped HDTV.

For PC World reviews of mainstream graphics cards, see our Top 10 chart.