AGP Last modified: Thursday, July 14, 2005
Short for Accelerated Graphics Port, an interface specification developed by Intel Corporation. AGP is based on PCI, but is designed especially for the throughput demands of 3-D graphics. Rather than using the PCI bus for graphics data, AGP introduces a dedicated point-to-point channel so that the graphics controller can directly access main memory. The AGP channel is 32 bits wide and runs at 66 MHz. This translates into a total bandwidth of 266 MBps, as opposed to the PCI bandwidth of 133 MBps. AGP also supports two optional faster modes, with throughputs of 533 MBps and 1.07 GBps. In addition, AGP allows 3-D textures to be stored in main memory rather than video memory. AGP has a couple important system requirements: The chipset must support AGP. The motherboard must be equipped with an AGP bus slot or must have an integrated AGP graphics system. The operating system must be the OSR 2.1 version of Windows 95, Windows 98 or Windows NT 4.0. And currently, many professional Macintoshes support AGP. AGP-enabled computers and graphics accelerators hit the market in August, 1997. However, there are several different levels of AGP compliance. The following features are considered optional: Texturing: Also called Direct Memory Execute mode, allows textures to be stored in main memory. Throughput: Various levels of throughput are offered: 1X is 266 MBps, 2X is 533 MBps; and 4X provides 1.07 GBps. Sideband Addressing: Speeds up data transfers by sending command instructions in a separate, parallel channel. Pipelining: Enables the graphics card to send several instructions together instead of sending one at a time. Also see Understanding Video and Graphics Adapters  in Webopedia's "Did You Know...?" section.
•E-mail this definition to a colleague• For internet.com pages about AGP . Also check out the following links! Accelerated Graphics Port (AGP)  Describes the various aspects of AGP, including its features and performance issues. This page is from "The PC Guide". Intel's AGP Home Page  Excellent collection of information about AGP including application notes, a tutorial, white papers, demonstrations, specifications, and an implementors forum. PC system bus reference guide  A complete look at the PC's system I/O buses. Includes coverage of the various functions and features of the bus, a look at ISA, VLB and PCI buses, plus older technologies, and the new AGP port. Information on the new AGP Compares AGP with PCI and provides features, benefits, and a list of companies supporting it. Video System Interfaces Describes the various video bus interfaces as well as related concepts. This page is from "The PC Guide."	Buses Video Memory 3-D graphics AGP Pro AGP texturing graphics Intel PCI PCI Express Give Us Your Feedback Graphics Cards AGP Products Compare Prices & Save on Graphics Cards at DealTime! Search by brand or type to find the best price across 100s of stores! Shop by Top Models: eVGA GeForce® FX5200, (128 MB) AGP Video Card 10 store offers from $37 - $45 PNY Verto® GeForce™ FX 5200, (256 MB) AGP Video Card 6 store offers from $49 - $63 eVGA e-GeForce® 7600 GT, (512 MB) AGP Video Card 2 store offers from $127 - $142 ATI RADEON® 9550, (256 MB) AGP Video Card 3 store offers from $30 - $30 ATI RADEON® 9600 Pro, (256 MB) AGP Video Card 2 store offers from $180 - $192