What Is an AGP in a Computer Motherboard?

Many older motherboards include an AGP slot.

An AGP slot provides a high-speed channel between a PC video card and motherboard. AGP, developed by Intel, stands for Accelerated Graphics Port. It appeared in the late 1990s to enhance 3D graphics, but its reign was short. The faster PCI-Express (PCIe) interface arrived in 2003.

Purpose

The AGP interface on a motherboard houses an add-on video card. The card handles 2D and 3D video processing, feeding a signal to the monitor via a port on the side of the card. Millions of AGP motherboards were installed on PCs, and AGP video cards remain available for purchase as of 2010. The fastest and most advanced cards, however, use the PCIe interface.

Versions

AGP replaced the older, slower PCI interface, not to be confused with PCIe. AGP appeared in three versions, the first offering a data transfer rate twice that of the PCI interface or bus. The final version, AGP 3.0, can move data 16 times faster than PCI.

Performance

Early AGP interfaces moved data at 266 megabits per second. The final AGP version's data throughput is 2.1 gigabits per second in 8X mode. This translated into faster frame rates and ever more photo-realistic images for computer users.

References

• Tom's Hardware: AGP - A New Interface for Graphic Accelerators
• Hardware Secrets: AGP Bus Tutorial
• Nvidia: AGP 8X