The Big Picture
Graphics chip and board makers update their hardware every six months or so, mainly to enable the development of more-complex, more-realistic PC games. But games aren't the only reason to get a new graphics board. Such features as support for two or even three displays, DVI ports (for digital flat-panel displays), a TV and/or FM radio tuner, and video connections--such as S-Video, Component, and, looking forward, HDMI--are other compelling reasons to upgrade.
Interface: Today's consumer graphics boards come with a PCI Express interface to plug into a PC's PCI Express slot. A few mainstream and value options with an AGP interface plug into the AGP slot on an older PC. You can't plug a PCI Express card into an AGP slot or vice versa. PCI Express graphics boards transfer data faster than AGP boards (theoretically 16X versus 8X), and the majority of new boards are PCI Express only.
Graphics processor: Today's graphics chips can efficiently handle sophisticated full-motion 3D video, thanks to advanced graphics processors, or GPUs. Right now, the GPUs populating most graphics boards for desktop PCs are developed by two companies: nVidia and ATI.
The faster your graphics processor, the faster graphics will render on your PC. How quickly a board can render game graphics--as measured in frames per second--gives you a good measure of its performance. Game graphics with 3D effects--such as pixel shading, transparency, or high dynamic-range lighting--will challenge a card, thus lowering frame rates. So will playing a game on a larger screen (at 1600 by 1200 resolution) and with antialiasing turned on (the feature smooths the edges of graphics).
Budget graphics cards do a fine job with older games. However, boards that can produce faster frame rates at a midrange screen resolution will typically sustain playable frame rates at higher resolutions, and they can usually handle more-complicated games. To play DirectX 10 games, you'll want a chip that supports DirectX 10 hardware acceleration.
At least one product on our power graphics board chart (as of 4/12/2007) offers two graphics processors on one board. While it does save the space and cost of configuring two boards in a dual-card configuration (see below), a dual-GPU board will cost you a lot and take up space inside your PC.
DirectX 10: Windows Vista's DirectX 10 technology promises visually richer applications and more-lifelike games, but you'll need a DX 10a??ready graphics card. The first DX 10 cards, which were based on nVidia's GeForce 8800 chip, cost at least $300, but new GeForce 8500 GT- and 8600 GT-based boards start at $90 and $150, respectively. In May, ATI announced its first DX 10 cards, including the $400 Radeon HD 2900 XT, plus the sub-$100 Radeon HD 2400 series and the $100-to-$200 Radeon HD 2600 series. Laptop buyers can now choose from ATI's Mobility Radeon HD 2000 Series and nVidia's GeForce 8400M or 8600M mobile chips.
For graphics boards that support DirectX 10 and that have been tested by PC World, go to the links for graphics boards on our Hardware Reviews Web page (prices as of April 2007).
Memory: When you use your PC for graphics-intensive activities, such as playing games or editing video, the information necessary to display images is buffered in graphics RAM. You'll need a lot of dedicated graphics RAM to handle today's complex, texture-rich games. The more complicated the game or image you're viewing, the more memory you'll need. These days, you'll easily find budget graphics cards with at least 256MB of DDR3 SDRAM (some may still come with 256MB of DDR2 SDRAM). You'll want this amount at a minimum, since, for Windows Vista, Microsoft's initial recommendations are to have a graphics board with 128MB of memory to run Vista's Aero Glass graphics-heavy interface. Mainstream and power graphics boards offer 256MB to 512MB of memory; 512MB is common on consumer-level power boards, though at least one board with two graphics processors (see below) offers 1GB of DDR3 SDRAM as of this writing (5/9/2007). Newer boards are starting to offer a theoretically faster DDR4 SDRAM as well.
For older games, 128MB is sufficient, though it's not likely to deliver high frame rates with new games or at resolutions above 1600 by 1200 pixels. For such demands, it's best to get a card with at least 256MB of video memory. Many games today don't require more than that, but you may want to opt for more memory rather than face upgrading again when new memory-intensive games arrive.
Some graphics chips that are integrated on a PC's motherboard (or in a laptop) use main system memory in lieu of dedicated graphics RAM, reducing the amount of memory available to the operating system. Less-expensive computers with lower-powered CPUs, such as Intel's Celeron, often have integrated graphics subsystems. Although PCs that use integrated chips do an acceptable job with typical business applications, they lack the extra memory necessary for sophisticated gaming, so they aren't usually suitable for playing any but the simplest games.
Two display ports: All new graphics boards offer two monitor ports. Some offer one DVI (digital) port and one VGA (analog) port. Others offer two DVI ports. DVI gives the cleanest signal to a digital LCD display; VGA, however, connects to a wider range of displays, particularly older types. You can plug a VGA monitor into a DVI port so long as you have a DVI-to-VGA adapter.
Enhanced video playback: Newer graphics boards have technologies--such as ATI's Avivo and nVidia's PureVideo--that enhance DVD playback, particularly at high-definition resolutions. Similar to what high-end DVD players do, Avivo- or PureVideo-equipped graphics boards can deinterlace images (remove artifacts) and scale them to fit your monitor.
HDCP support (High-Bandwidth Digital Content Protection): This is an up-and-coming feature whose wrinkles aren't completely ironed out as of this writing (5/24/2007). For a graphics board to be able to play an HD DVD or a Blu-ray Disc movie, it must support HDCP to decode movie studio copyright protection. HDCP support is a complex issue. The GPU, graphics board, monitor, and DVD player must all support HDCP, or else you won't get full-resolution HD.
Some graphics cards state HDCP compliance in their specs, or boast HDTV output, but don't actually implement HDCP (only implementation earns a "certified" moniker). Look for a card based on an nVidia GeForce 7- or GeForce 8-series GPU with PureVideo HD drivers, or for AMD's ATI Radeon X1650 or better card with the latest Catalyst drivers. Even if a board has one of these chips, however, that doesn't guarantee it implements HDCP. nVidia grants its PureVideo HD logo only to certified cards. See "High-Def Movies on a PC" (part of our "High-Def Video Superguide") for more information on the pitfalls of playing HD content on your PC.
S-Video-out/-in: The S-Video-out port allows you to send video signals to a TV, projector, or other display or recording device. The S-Video-in port lets you bring video into your PC from a camcorder or the like. By the way, if you see the term VIVO (Video In Video Out) advertised with a graphics board, it means that the board has video in and out through one connector.
Composite-out/-in: Composite ports fulfill the same function as S-Video ports, but deliver video that is noticeably lower in quality than S-Video. However, composite ports are particularly handy for use with older devices, which may lack S-Video ports. Many graphics boards that provide S-Video ports also include an S-Video-to-composite adapter cable.
TV tuner: If you want to play and/or record live TV on your PC, you'll need a graphics board with a TV tuner. Several midrange and power boards with such tuners are available.
Overclocking: Running a graphics processor faster than the manufacturer's specified speed is popular among PC tweakers and dedicated gamers. While it carries risks such as overheating, when done within vendor-specified safety limits, it's a viable way of eking extra performance out of a midrange or power board. Some vendors--BFG Technologies is one--sell cards that have already been overclocked; others bundle overclocking software with cards; and some manufacturers, like ATI, don't officially support it. Be sure to read the manufacturer's recommendations and instructions before overclocking.
Antialiasing: Most cards offer antialiasing, which smooths and softens the jagged edges of 3D images. This feature is especially helpful at lower resolutions. Enabling it can lower frame rates, though, so gamers have to choose between smoother images and faster performance.
Dual-card support: Running two graphics boards simultaneously within one PC appeals to gamers who want the most graphics performance they can get for their graphics-heavy PC games. To run two graphics boards, make sure you have a motherboard that supports either nVidia's SLI (Scalable Link Interface) or ATI's CrossFire dual-board technologies. At the high end, a two-card configuration makes the most sense. In the mainstream range, a recommendation isn't so clear. See "Two Cards or One, That Is the Question" (a section of "Greater Graphics") for more information.
All the graphics boards on our power and mainstream charts (as of 5/24/2007) support nVidia SLI or ATI CrossFire technologies for harnessing the power of two boards in one PC. The majority of the boards in the value chart supported SLI or CrossFire, but a couple of models did not.
Quad SLI: nVidia's Quad SLI technology lets you combine four graphics chips in one PC. Initially, you couldn't build a Quad SLI configuration yourself--you had to order one from a company specializing in building high-end PCs. Now, however, nVidia has drivers so you can build your own Quad SLI setup. Quad SLI will let you play games at massive resolutions such as 1920 by 1200 and 2560 by 1600; and it really shines when you turn on high-end antialiasing and anisotropic filtering settings. For more information on what Quad SLI can do, read "GeekTech: nVidia's Powerful, Complicated Quad SLI."