You Can Count on AGP

By ClockWeb

AGP Port? What is it?
AGP (Accelerated Graphics Processor) which was developed and released by Intel last year, is now making inroads into home PCs. AGP can render heavy duty texture mapping which greatly enhances the graphics quality of 3D games. Some 2D applications, such as teleconferencing video, could also benefit from AGP's high bandwidth too.

AGP & Texture Map
Texture maps are like wallpaper. These can be plastered onto any coputer-generated surfaces in a 3D scene. Texture maps can be created from scanned photographs of "real" surfaces like marble or wood surfaces. They can also be intricate patterns that are computer generated.
When applied in a 3D scene, texture maps add to its realism. For instance, a texture-mapped computer-generated wall will appear like an authentic brick wall, complete with grains and bumps. Texture maps can even be dynamic. For example, game developers can map a video clip onto any surface, complete with sound and live movements.
Today's PC games do not incorporate highly-intricate texture maps because they are such memory hogs ( a single texture map rendered at 640x480 pixels easily consumes more than 1 MB of video memory) and these effects can overwhelm the cramped frame buffers of today's video cards.
Frame buffers are on-board memory bank on video cards that are used to store bitmapped images while it is being painted on screen. And in the context of home computing frame buffers are pricey.

Using System Memory
Unlike today's PCI-based video cards, which relies entirely on frame buffers, AGP-based graphics accelerators can call on as much memory as the system has, thereby circumventing this memory bottleneck by putting a portion of the video data into the system memory. This frees up precious video memory for storing other video data, especially those that are likely to be accessed constantly.

Faster Bus Speed
But the trick is to enable the video card to access system memory quickly for realistic animation on-screen. This would be impossible with the PCI bus. AGP is a direct connection between the display adapter and system memory. It moves data at the speed of the system bus (66MHz), or twice the speed of the 33MHz PCI bus. It also use a "double-clocking" technique which doubles the transfer rate. AGP can thus achieves a 133MHz operational rate, which translates to a 533 megabyte per sec burst data transfer rate. AGP-equipped motherboards is becoming a norm. Pentium II boards have one AGP slot, which goes with an AGP-compliant display adapter. Besides getting a great graphics performance, you can also free up the PCI slot that hosts the display adapter. With AGP, game developers now have more room to manoeuvre when it comes to incorporating cool graphics. When they do, expect liquid smooth, lifelike 3D scenes.