Accelerated Graphics Port (AGP)

Accelerated Graphics Port (AGP) is an interface specification that enables 3-D graphics to display quickly on ordinary personal computers. AGP is designed to convey 3-D images (for example, from Web sites or CD-ROMs) much more quickly and smoothly than is possible today on any computer other than an expensive graphics workstation. It is especially useful in conjuction with gaming, three-dimensional (3D) video, and sophisticated scientific/engineering graphics programs.

The interface uses your computer's random access memory (RAM) to refresh the monitor image and to support the texture mapping, z-buffering, and alpha blending required for 3-D image display. AGP offers high-speed data transfer to and from RAM, optimizing the use of memory and minimizing the amount of memory necessary for high-performance graphics. The AGP main memory use is dynamic, meaning that when not being used for accelerated graphics, main memory is restored for use by the operating system or by other applications. AGP runs at several times the bus speed of conventional Peripheral Component Interconnect (PCI). Because of this, the data transfer rate using AGP is significantly greater than with PCI video cards. AGP employs eight sideband address lines, so multiple data transfers can take place concurrently.

Intel, which took the lead in developing its specifications, introduced AGP into a chipset for its Pentium microprocessor. The newer, faster microchips in Intel's Pentium line are designed to work with the AGP chipset. Intel says the advanced floating point unit and faster cache algorithm of the more advanced Pentiums are better adapted for 3-dimensional applications.

This was last updated in September 2005

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