PC Hardware A Beginner’s Guide

(^224) PC Hardware: A Beginner’s Guide
The PCI bus supports 32-bit and 64-bit interfaces and full Plug-and-Play
capability, which provides nearly foolproof installations and configurations.
Its shorter slot length helps keep motherboards small, one of the reasons
for its popularity. Figure 11-5 shows an example of a PCI expansion card.
 AGP (Accelerated Graphics Port) While this expansion bus is an expansion
bus like the ISA and PCI buses, it is used for only one type of expansion
card—video cards. It was developed primarily to improve 3D graphics.
Another objective of AGP was to make video cards less expensive by removing
memory from the video card, but because memory became less expensive, its
benefit is largely in 3D graphics performance. AGP runs at faster speeds than
the PCI bus. There are different speed ratings for AGP video cards: 1xAGP,
2xAGP, and 4xAGP, which transfer video data at 264Mbps to 1Gbps. The
brown AGP slot is just a little shorter than the white PCI slot and is usually
nearby. Figure 11-6 shows the placement of the AGP slot on an AT form factor
motherboard in relationship to the ISA and PCI slots.
Figure 11-4. Common PC expansion slots