There are four different current graphics card interfaces: integrated, PCI, AGP
and PCI-Express.
Most retail computers will ship with an integrated graphics card. This means
that if you want to play new 3-D games you will need to upgrade. Most motherboards
that have integrated graphics will also have one of the other three slot
interfaces available so it isn’t hard to place a new card to suit your needs if the
need ever arises.
Older video cards use the standard PCI slots that are now growing obsolete
due to limited speed and memory. These cards are needed for a few rare systems
lacking an AGP or PCI-E slot (usually low end desktop systems designed to be
cheap.) They are also useful for adding aditonal video cards to a system.
Although the AGP standard has now, by and large, been superseded by PCIE,
the cards are still available as are a few motherboards that support them.
There are 4 different speed and bandwidths of AGP, 1x, 2x, 4x and 8x. While
8x is the fastest and most common for high end products, the true performance
of your AGP card is limited by the lower AGP value of your graphics card and
motherboard. For example, an AGP 8x card on a 4x motherboard can only run
at up to 4x. AGP has mostly been phased out and there will not be an AGP
16x due to technical limitations.
The newest trend in graphics card is the PCI-Express (not to be confused
with PCI-X) system that supports up to 16x speeds. Some graphics cards still
come in both AGP and PCI-E 16x models but the newest models of graphics
cards are often PCI-E 16x only. While most motherboards have only one PCI-E
16x slot, those with two such slots can combine the power of two video cards
using technologies known as SLI for NVidia, and CrossFire for ATI. However,
you will have to match the video cards to a motherboard supporting the multiple
card technology of choice, and use two similar video cards that both support
dual video cards.
Keep in mind that to provide best picture quality your graphics card must
be capable of displaying the same resolution as your LCD display’s native resolution.