n. Besides increased performance at high resolution, you get enhanced video playback for multimedia applications and 3-D game acceleration.
Having just tested 13 PCI graphics accelerator cards, we can tell you something about the current state of 2-D graphics performance. All our test cards support 24-bit color at 1024- by 768-pixel resolution or above and with high refresh rates. (This typically requires 4 MB of card memory.) With this in common, there is still much to differentiate the boards in terms of their video and 3-D capabilities. Some also have special features like TV display and support for multiple monitors. The best news is that you don't have to spend much money these days to get a good card.
In fact,
our Best Overall choice, the GrafixStar 450 from VideoLogic, costs only $149 when loaded up with 4 MB of memory. The GrafixStar 450 and other low-cost cards like the $159 Hercules Dynamite 128 both provide excellent 2-D performance. At the other end of the price spectrum is the 8-MB Integrated Micro Solutions (IMS) Twin Turbo 128P8, which provides 24-bit color at 1600- by 1200-dpi resolution for $599.
Performance Factors
The biggest factor in graphics card performance is the accelerator chip set. In our tests, the best performers use S3's new Virge chip set, which accounted for the three top 2-D performance spots. Not all Virge cards did well: STB's Velocity 3D hung at the back of the pack. Matrox's Millennium, a former champ, still does well with Matrox's MGA-2064W accelerator, and Hercules' Dynamite 128/Video took fifth place using another new chip set, Tseng Labs' ET6000. Architectural bus width -- as in 64 bits versus 128 bits -- appears not to matter.
A card's graphics accel
erator chip plays a big part in its performance, but so does the Windows driver software. Driver code most likely accounts for the STB Velocity 3D's slower performance compared to other Virge-based cards. The top-notch performers jockey for position from month to month as vendors come out with new driver software.
Having more graphics memory increases capabilities and performance. The type of memory is important, but less so than it used to be. Whereas dual-ported VRAM always provided better performance for higher resolutions and color depths than DRAM, there are newer and less expensive alternatives such as extended data out (EDO) DRAM, multibank DRAM (MDRAM), and synchronous DRAM (SDRAM) that do nearly as well.
3-D and Video Capabilities
The latest graphics cards have on-board 3-D accelerators that mainly aid gaming performance. While development of low-end 3-D graphics accelerators has been driven by the computer games market, the games themselves illustrate how far 3-D graph
ics has come. As is happening with multimedia, 3-D imaging techniques may eventually turn up in mainstream applications.
3-D acceleration on the graphics card helps the system's CPU turn a mathematical model of a 3-D object into a 2-D representation. Quickly shading, applying texture, and accurately representing object depth affect the speed at which still images are rendered, but these kinds of operations also affect the smoothness of animated 3-D sequences, particularly at greater resolutions and color depths.
For the games market, Microsoft's Direct3D (D3D) API for Windows 95 promises to be important because it provides games developers with a common API that is more or less independent of any graphics chip. All the cards we tested were D3D-capable. The cards that do best on our D3D Tunnel tests, such as the ATI 3D Xpression, the Matrox Mystique, and the Matrox Millennium, are excellent choices for game-type environments.
Microsoft also supports the OpenGL 3-D API in Windows 95 and NT. Curren
t boards have some OpenGL hardware acceleration capabilities, but they still have a long way to go compared to high-end 3-D cards. Our testing for OpenGL showed that some of the cards are faster than others, but there's not much spread.
If you use video clips in multimedia presentations, you should check out a graphics accelerator with MPEG hardware acceleration. It will speed up and smooth out playback by efficiently compressing and decompressing graphics and sound data. The Matrox and Number Nine adapters, and the Virge VX-equipped adapters (STB Systems Velocity 3D, Diamond Stealth 3D 3000, ELSA America Winner 3000-L) have integrated video components, and some others have MPEG options or at least software MPEG players.
The cards with hardware MPEG help attain the full-screen playback rate of 30 frames per second, which provides the appearance of full-motion video. While current MPEG hardware decompression is imperfect, overall it's still better than software-based video playback. Current software MP
EG decoders are just on the edge, with performance that's perhaps adequate for short video clips in reference works, such as a CD-ROM encyclopedia. With the availability of TV-tuner daughtercards on some graphics boards, it seems that the sky's the limit for viewing video on your PC screen.
While performance is the primary factor to consider when buying a graphics card, bundled software can make a card easier to configure and use. Most of today's adapters have utilities for installing drivers, changing resolutions on-the-fly, zooming in and panning around the desktop, and even creating virtual desktops larger than the screen.
Contributors
Dorothy Hudson, project manager/NSTL
Jim Kane, project manager/NSTL
John McDonough, technical writer/NSTL
Dave Rowell, senior technical editor/BYTE
illustration_link (54 Kbytes)
Illustration based on ELSA's Winner 3000-L.
13 Graphics Cards for Business
