How It Works: Graphics Boards

Which Graphics Board Is Right for You?

Since the earliest days of PC-compatible computers, PC makers have used graphics boards to speed up the display process. The earliest PCs used graphics boards to take the load off the CPU when it had to render each character in the text-based DOS environment. With the advent of modern GUI operating systems like Windows--and 3D games--rendering got more complex, and graphics boards became much more critical.

As the graphics board market matured, 3dfx, with its Voodoo line of graphics accelerators, quickly became king of the 3D graphics board market. But over time, other companies began to challenge 3dfx's market dominance: NVidia, with its GeForce line (currently the only major line of graphics chips licensed to multiple manufacturers), has wrested the throne away from the erstwhile monarch.

While the two giants still battle it out for supremacy in the graphics board arena, other companies have managed to chip out a handhold, as well. ATI, always a stalwart competitor in the budget graphics board market, recently stepped into the high-end ring with a new line of boards powered by a GPU it calls Radeon. Led by NVidia, the graphics chip set development cycle for the entire industry has sped up to six months, with each vendor releasing a major new GPU chip set at least once a year. Other companies such as Matrox, SiS, and S3 compete in the medium- to low-end graphics board market.

Most of today's graphics boards use at least 32MB of video memory. While these boards capably render the flat 2D graphics of office applications and Web browsers, they shine when used for 3D gaming. The midrange boards will run you between $200 and $300. Many boards, such as those using NVidia's GeForce2 chip set, use faster Double Data Rate SDRAM memory, which doubles the speed by transferring data twice with every "tick" of the memory's clock, instead of just once.

The most advanced boards ship with a minimum of 64MB of onboard video memory, the most powerful GPU chip sets, and advanced 3D rendering capabilities. These powerhouse boards, capable of fill rates in the gigapixel-per-second range, sell for close to $400 and offer other advanced features such as hardware transform and lighting, which can speed up frame rates in games that support it, and full-scene antialiasing to clean up 3D images at low- and midrange resolutions.

All PCs ship with basic graphics capabilities: This can include a board based on an earlier generation chip set (such as a 3dfx Voodoo3, a Matrox Millennium G200, or an NVidia TNT2 GPU) or one of the budget-targeted boards (ATI's 3D Rage Pro, 3dfx's Voodoo4, or NVidia's GeForce2 MX), streamlined boards with the latest 3D graphics abilities but not all the bells and whistles.

The least desirable option for people who use 3D applications is an integrated graphics GPU built into the PC's motherboard. In an integrated graphics PC, you'll usually find a low-end graphics processor and a minimal amount of video memory (4MB to 8MB), some of which might be shared with normal system memory. This memory sharing allows PC makers to sell new PCs for as little as $300 but often leads to slowdowns when handling intensive graphics applications.

Other valuable features you might find in graphics boards include video input and output--a necessary addition for video editing and feeding to a television or VCR; DVD acceleration, to enhance DVD-video playback; DVI output, for the digital visual interface used by digital CRT displays and some flat-panel monitors; and multiple-monitor support.

The Future of 3D Graphics

In recent years, graphics board manufacturers have focused on 3D gaming as the primary driving force to develop new boards, according to Peter Glaskowsky, a senior analyst for 3D and multimedia at Cahners Microdesign Resources. But that will change. "Microsoft would like to integrate more 3D into the user interface, and in the next year or two they'll be in a position to make the whole Windows interface 3D. At that point, 3D will matter much more to the average user," he says.

Other options, such as integrated graphics, continue to grow because of their lower cost. (Jon Peddie Associates estimates that of the 160 million PCs that will ship this year, 100 million will use integrated graphics.) But most analysts feel that the 3D graphics board industry has a long life ahead of it.

"The ability to generate something that looks as good as Toy Story is only a few years away," says Glaskowsky. But duplicating photorealism in real time will probably take until 2010, he says. Perhaps another 10 to 20 years will pass before graphics boards emerge with power to make the trillions of floating point calculations required to replicate the subtlety of real life.