In order to interact with a computer (enter your information and see the results) we need both an input device and an output device. For example we enter our information with the keyboard, mouse, or microphone, and the computer outputs sound and / or visuals.
The visual output that a computer provides is handled with the video card. This is dedicated circuitry that interprets information from the CPU (Central Processing Unit) and sends it to the computer monitor. Modern computer systems with Graphical User Interfaces (GUI) such as Microsoft Windows rely on fairly sophisticated video output to provide information to the user.
Because they are a necessary part of the computer, many motherboards have built in video processors. These are suitable for everyday computing tasks such as word processing and e-mail. Other applications such as video editing, graphical design work, and high end games require specialized video cards capable of 3-D rendering.
Types of Video Cards
Integrated video graphic cards are part of the motherboard. They are connected directly to a monitor and require no extra cards. This is the least expensive type of video adapter, and requires no special consideration for installation. Simply plug the monitor in and go!
The drawback of integrated video is the relatively limited performance it offers, especially for applications requiring 3-D rendering such as games and graphic design. In addition, not every motherboard has integrated video.
If you need to buy a video card, you must know which type of card your motherboard accepts. AGP (Advanced Graphics Port) has been the standard for several years now, but is gradually being replaced by PCI-Express. Almost all the high-end video cards use PCI-Express, so if you have special graphics needs make sure your motherboard has this kind of slot.
AGP is still popular for low and midrange video cards, and will probably remain available for a few years to come.
Specs
What makes a video card high-end? Two basic things -- the quality of the video processor and the amount of memory. Just when you thought you had your computer's memory requirements down pat, along comes another type of memory -- video memory.
Video cards have their own integrated memory chips. A certain amount of memory is needed just to get an image on the monitor. Eight megabytes, for example, is required to display a screen resolution of 1600 x 1200.
Most video cards have a minimum of 32 MB or 64 MB, and the extra memory is used for 3-D imaging and enhancing the refresh rate to provide a more stable display. The maximum amount of memory on current video cards is 640 MB. This is on a card designed for professional graphic design.
As a general rule of thumb, 64 MB is suitable for everyday computing like word processing and Internet browsing. Computer games and video editing applications need cards with 128 MB to 256 MB.
Besides memory, the second factor that determines the quality of the video card is the processor -- sometimes called the GPU (Graphics Processing Unit). Modern GPUs are extremely efficient in 3-D video rendering and, like CPUs, require their own dedicated cooling fan.
Prices
The type of video card that is suitable for your computer depends on what kind of applications you use. If you will not be playing the latest computer games, you can get by with a 64 MB PCI or AGP card for less than $50.
Serious gamers should look at cards in the 256 MB range. These will set you back about $100-$200 for an AGP 8X or
PCI-Express card.
People who are doing video editing need graphics cards which have Video In/Video Out (VIVO) capabilities. These specialized cards can cost between $200 and $500.
Whatever video card you decide on make sure it does all the things you really need it to do.
