Expansion Cards - How a Computer Works (2015)

How a Computer Works (2015)

10. Expansion Cards




Expansion cards plug directly into the motherboard. This enables them to connect to local or system buses. Expansion cards are used for communicating with devices/ peripherals as data can be moved to them at a much higher speed than using USB ports.



Most expansion cards centre around the PCI bus standard. The 32-Bit PCI local-bus card is closely integrated with plug and play and is the most common card used in PCs.

The card handles 32 bits of data at one time.



An adaption of the PCI slot design is used to connect a 32-bit Accelerated Graphics Port (AGP) card. This is used to interface a monitor to the motherboard.

Graphics Card


The AGP is designed to accept only graphics cards as with the PCI card an edge connector that forms part of the PCB slides into a special connector on the motherboard. This connector differs from the one on the local PCI bus.