The video graphics card was initially intended as just a connection port for the monitor, but it has now become one of the most important components inside a computer. The first card was launched in 1981 as part of the hugely successful IBM PC and could only display a few lines of text in one color. Modern cards are almost as powerful as a computer and can draw complex and realistic three-dimensional scenes. Over the years, an increasing amount of work has shifted away from the main processor to the graphics processor. The addition of onboard memory to the cards has also resulted in a shift away from using the system memory.
The video graphics card is much like any other computer expansion card. It is a large circuit board with chips, contacts, plugs, and a bracket. Most cards also have a fan and heatsink to remove the large amount of heat generated. Without these cooling devices, the graphics processor could overheat and cause visual problems or it could even destroy itself. Many new motherboards now come with onboard video support, eliminating the need for basic graphics cards. But there will always be a need for advanced cards to run intensive video games and graphics software.
The expansion slot used for a video graphics card depends mostly on the age of the card. Older cards typically used the AGP slot, and some even used a regular PCI slot, but most recent cards use the faster PCI-Express slot. Two or more cards can be joined together using an SLI connector, provided that the cards and the motherboard all support SLI. The main output plugs on a video graphics card are either VGA or DVI. Some cards have both a VGA and DVI plug, while other cards have two of the same. Adapters are available that convert a one type of plug into another, and most new cards come with an adapter included.
The amount of heat generated by a video graphics card depends on the power used by its processor. Basic cards use little power and only need a small heatsink but advanced cards use more power and need a fan attached to a large heatsink. There may also be a plastic guide to direct air through the heatsink and out the back of the case. Cooling fans are responsible for most of the noise that comes from a computer. Some cards use silent heatpipe coolers instead of fans to eliminate noise. Pipes filled with a fluid distribute the heat more evenly around the heatsink and provide more efficient cooling than a regular heatsink.
The installation of a new video graphics card is a simple task that can be done by most computer users. The computer and monitor must be turned off before the case cover and monitor plug are removed. Some cards have other cables attached to them which also need to be removed. The screw holding the bracket to the case is removed and the old card pulled out of the slot. There is often a latch that also needs to be undone before the card can be removed. Once the new card has been pushed into the slot, the bracket can be screwed to the case. The cables are then connected and the case cover put back on.
The software used with a video graphics card is just as important as the card itself. Developers use a graphics library to instruct the card what to draw. A library needs to be installed on the computer before any programs coded with it will work. The most popular libraries are DirectX and OpenGL. Microsoft’s DirectX can be found on virtually every computer that has Windows installed. OpenGL was developed by Silicon Graphics and can be used with Windows and other operating systems, such as Linux and Mac OS.