A desktop video card also referred to as graphics card, video adapter or graphic adapter is a piece of hardware in your computer that is responsible for generating what you see on your computer's screen. It is the video card that identifies which dots on the screen are to light up based on the signals it receives from the processor and even specifying the color of each dot (known as a pixel). But that is just the basic functionality. Many video cards nowadays have additional features such as video capture, 3D scenes, 2D graphics, FireWire, TV-tuner adapter, light pen, and TV output as well as the ability to project images across several monitors.
Most desktop video cards are detachable from the mother board and have a port at the back to which the monitor cable connects. Some desktop video cards use the computer's RAM while others are programmed to use their own memory known as video memory. The quality of video cards that computers are fitted with have a direct effect on the quality of the monitor's output as well as the end user's experience. One area where the quality of video cards gains prominence is in gaming.
Many of today's computer games require video cards that have a certain minimum level of functionality. The most prominent functionality required of desktop video cards that will be used for gaming is known as 3D acceleration. Since many forms of gaming are characterized by fast moving and changing images, the video cards must have the ability to rapidly switch these images in tandem with the changing flow of the game. The absence of a video card with 3D acceleration will often result in the game not loading.
But good quality video cards are not only important for gamers. A low quality desktop computer video card can make using the PC uncomfortable, cause eye strain and lead to general fatigue. Low quality cards have a weak refresh rate and are more prone to computer freeze when subjected to applications that require a high refresh rate. It is not uncommon to trace frequent computer crashes and instability to a faulty video card.
To keep with growing end user demands, desktop video cards are becoming more and more sophisticated. Some video cards are fitted with an advanced processor that allows the card to compute complex calculations and make logical decisions without the need to send the jobs back to the main processor for computation. The capacity of video memory has also continued to increase over the years in order to accommodate the ever larger files and images that the video card can handle.
But this ever increasing capacity and capability of desktop video cards comes at a price - heat. The handling of ever larger files and demands for ever faster processing means the card generates a substantial amount of heat that if left unchecked, can damage not just the card but adjacent components. So even as you buy a video card, you must be certain that the cooling mechanism (built into the card or as part of the motherboard) whether implemented through heat sinks or fans, will be adequate.