AGP Expansion Slot

AGP Video Card

The AGP expansion slot connects AGP video cards to a motherboard. The video card shown above is an AGP GeForce FX 5500. Video expansion cards are also known as graphic expansion cards. AGP stands for Accelerated Graphics Port. AGP video cards are capable of a higher data transfer rate than PCI video cards. Video cards, like the one shown above, simply plug into an AGP slot and connect a monitor or other video display device to a computer. The "DVI Out" connector shown in picture above connects to a digital video display. DVI stands for Digital Video Interface. Video cards with a TV output connection are capable of displaying a computer's video on a television. Video cards with a TV input connection are able of displaying a television's video on a computer. The AGP card and the monitor are what determine the quality of a computer's video display. The photo below shows what an AGP slot looks like.

AGP Slot

AGP slots and cards come in 4 different modes. You must be careful to match the card and slot with the correct mode. Some cards and slots are capable of running in more than one mode. AGP 1x mode is the oldest. It transfers data at 266MBs per second. AGP 2x mode transfers data at 533MBs per second. AGP 4x mode transfers data at 1.07GBs per second. The latest AGP mode is AGP 8x. It transfers data at 2.14GBs per second. Below is a picture of three PCI Express slots.

PCIe Slots

PCI Express is a more recent technology that is slowly replacing AGP. PCI Express x16 slots can transfer data at 4GBs per second, which is about double that of an AGP 8x slot. PCI Express slots come in PCIe x1, PCIe x2, PCIe x4, PCIe x8, and PCIe x16. PCIe x16 slots are used for video cards.


The photo above shows what a GPU looks like. GPU stands for Graphics Processing Unit. The video card is in charge of controlling the video display. Much like the CPU's relationship with the motherboard, the brain of the video card is the GPU. It is responsible for making the decisions for processing the video card's graphical input and output data. It is hidden under a fan and heatsink in the first picture to keep it cool so that it doesn't overheat.