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Computer Components: What is a Video Card?

written by: heatherlorrmay•edited by: Rebecca Scudder•updated: 5/27/2009

Have you ever wondered how the images on your computer monitor are created? The video card is the workhorse of your entire computer.

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    Video Cards

    The images appearing on your computer monitor are made of tiny dots called pixels. Modern computer monitors are able to display over a million of these pixels at any one time. Even while processing the data and commands your software creates, your computer still has to decide what to do with the pixels in order to create one image. To provide your PC with the images you need, there is a dedicated component inside your computer: the video card. Without dedicated video components the task of creating something on your computer’s monitor would be too much for your computer to handle.

    The video card is one of the hardest working components in your computer. Every image that your monitor projects to you starts out as digital information from which a wire frame of straight lines is created. Then the image is filled in, lighting, texture, and color is added and the image is broken down into pixel information and projected through your monitor. This happens at least sixty times a second and must be completed for each window you have open. Text is of course easier to process than images or photos. But look at your word processor or email program; each icon, each sidebar, each smiley face is an image that must be processed by the video card.

    To keep your computer running at top speed, video processing has been moved from the main CPU and processing chips to a separate video controller. Today there are different types of video controllers available: a dedicated video expansion card that can be plugged into a slot on your computer’s motherboard or a graphic chip embedded on the motherboard. The video card is built like a mini-motherboard but instead of controlling the processes for the entire computer, this mini-motherboard has one job — create the necessary images. In a video card, there is a graphics processing unit (GPU) which operates in a similar manner to the main CPU and a piece of software called the video BIOS (or firmware). This software has only one function, to provide the necessary digital instructions to monitor the video card's operations and allow the video card to move the created images to your monitor.

    When you connect your monitor to your computer, you are actually connecting directly to the video card through the video port on the computer. The cable that you use to connect the monitor to your computer is probably either a DVI or HDMI standard connection. These connection types are video connections based on a digital standard that was created to provide flat-planel displays such as LCDs and plasma screens with a high quality video signal that has very limited amounts of image distortion or electrical noise. Before DVI became popular most monitors were connected through a VGA connection which provided a very good image without the high definition that DVI and HDMI are able to produce.

    Video cards can be as elaborate as a motherboard. Many video cards include their own heat syncs or fans designed to remove the heat created by the GPU, and sometimes the video card has its own RAM memory. Some video cards are as expensive as a new CPU and are marketed as necessary upgrades for your computer. Usually high end computer games require the top of the line video card in order to provide the gamer with the level of graphic animation and gameplay that has been advertised, but for the most part if you are not having issues with the video output of your computer you can put off replacing your video card until it is time to purchase a new computer.

    Understanding your computer:

    >>>>What is the Motherboard?

    >>>>What is the CPU?

    >>>>What is RAM?

    >>>>What is the Hard Drive?

    >>>>What is the Video Display?

    >>>>What is the CD-Rom/DVD?

    >>>>What is USB?