Specifications

3D Graphics Accelerators
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most video adapters began to take on many of the tasks involved in rendering 3D images, greatly less-
ening the load on the system processor and boosting overall system performance.
There have been roughly eight generations of 3D graphics hardware on PCs, as detailed in Table 15.19.
Table 15.19 Brief 3D Acceleration History
Generation Dates Technologies Example Product/Chipset
1st 1996–1997 3D PCI card with passthrough to 2D 3dfx Voodoo
graphics card; OpenGL and GLIDE APIs
2nd 1997–1998 2D/3D PCI card ATI Rage, NVIDIA RIVA 128
3rd 1999 2D/3D AGP 1x/2x card 3dfx Voodoo 3, ATI Rage Pro,
NVIDIA TnT2
4th 1999–2000 DirectX 7 API, AGP 4x NVIDIA GeForce 256, ATI Radeon
5th 2001 DirectX 8 API, programmable vertex NVIDIA GeForce 3,
and pixel shaders NVIDIA GeForce 4 Ti
6th 2001–2002 DirectX 8.1 API ATI Radeon 8500, ATI Radeon 9000
7th 2002–2003 DirectX 9 API, AGP 8x ATI Radeon 9700, NVIDIA GeForce
FX 5900
8th 2004–2005 PCI Express ATI X800, NVIDIA GeForce 6800
With virtually every recent graphics card on the market featuring DirectX 8.x or greater capabilities,
you don’t need to spend a fortune to achieve a reasonable level of 3D graphics. Many cards in the
$75–$200 range use lower-performance variants of current high-end GPUs, or they might use the pre-
vious year’s leading GPU. These cards typically provide more-than-adequate performance for 2D busi-
ness applications. Most current 3D accelerators also support dual-display and TV-out capabilities,
enabling you to work and play at the same time.
However, keep in mind that the more you spend on a 3D accelerator card, the greater the onboard
memory and faster the accelerator chip you can enjoy. Current high-end video cards featuring
NVIDIA or ATI’s top graphics chips, 128MB–256MB of video memory, and AGP 8x or the new PCI
Express x16 interfaces sell for $300–$500 each. These cards are aimed squarely at hardcore gamers for
whom money is no object. Mid-range cards costing $200–$300 are often based on GPUs that use
designs similar to the high-end products but might have slower memory and core clock speeds or a
smaller number of rendering pipelines. These cards provide a good middle ground for users who play
games fairly often but can’t cost-justify high-end cards.
Before purchasing a 3D accelerator adapter, you should familiarize yourself with some of the terms
and concepts involved in the 3D image generation process.
The basic function of 3D software is to convert image abstractions into the fully realized images that
are then displayed on the monitor. The image abstractions typically consist of the following elements:
■ Ver tices. Locations of objects in three-dimensional space, described in terms of their x, y, and z
coordinates on three axes representing height, width, and depth.
■ Primitives. The simple geometric objects the application uses to create more complex construc-
tions, described in terms of the relative locations of their vertices. This serves not only to spec-
ify the location of the object in the 2D image, but also to provide perspective because the three
axes can define any location in three-dimensional space.
■ Textures. Two-dimensional bitmap images or surfaces designed to be mapped onto primitives.
The software enhances the 3D effect by modifying the appearance of the textures, depending
on the location and attitude of the primitive. This process is called perspective correction. Some
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