AGP card

Synonyms

Accelerated graphic port
Advanced graphic port

AGP Overview

AGP is standard for graphic cards. It allows attaching graphic card to the motherboard. AGP interface is compatible for 3D applications. The standard includes bus computer specifications and expansion slots. Today almost every computer contains built-in AGP slots. AGP interface accelerates the graphics by providing a dedicated path (pipelined access) to main memory

AGP Speed

The AGP standard allow speed compatibility. It backward compatibility allows a 4X device to run at 2X and 1X speed.

AGP Voltages

Various AGP versions work at different voltages. The concern with voltage is the card and motherboard should be given same voltage. AGP 1x and 2x works at 1.5 Volts or 3.3 volts. AGP 4x works at 1.5 or .8 volts. AGP with speed 8x works at .8 volts.

AGP Connectors

AGP slots contains connectors where graphic cards to be fit. The connectors are keyed to specify functional voltage levels. The connectors are of two types and so does the keys. A male connector absence of area indicates the key. In a female connector raised area defines the key. One key specifies 1.5 volts and the other specifies 3.3 volts functionalities. Both the keys induce a third voltage of .8 V operations for 8X speed.

AGP Versions & Specifications

AGP 1.0

AGP 1.0 supports two speeds, 1X and 2X. Allows only one connector keyed for 3.3 volts function. 1X allows 266 Mbps and 2X 533 Mbps data rates.

AGP 2.0

AGP 2.0 comes in three modes: 1X, 2X and 4X. Supports either 1.5 Volt, 3.3 volts or both connector-keyed. 1X allows 266 Mbps, 2X 533 Mbps, and 4X 1.07 Gbps data rates.

AGP 3.0 / AGP Pro

AGP Pro is the most enhanced version of all. It comes in four modes: 1x, 2x, 4x, and 8x.1x allows 266 Mbps, 2x 533 Mbps, 4x 1.07 Gbps, and 8x 2.1 Gbps data rates. AGP Connector keyed for 1.5 volts function. AGP 3.0 supports AGP 1.0 and 2.0 compatible cards.

AGP and PCI

AGP bus width is 32-bit with running at full system bus speed. In PCI it utilizes only half of the system bus width which means AGP is twice faster than PCI. On 66MHz processor the AGP will run at 66MHz but PCI will at 33 MHz. Moreover AGP itself has 2X mode that send the data at twice rate as processor.

AGP Requirements

To have an AGP access the following components are necessary.

• AGP Video Graphic Card
• Operating system must support the AGP standard and support for AGP drivers.
• AGP must be compatible with the motherboard standards.