Graphics Acceleration

A graphics acceleration is a process of sending and refreshing of images to the display monitor and the computation of special effects common to 2-D and 3-D images. Graphics accelerators speed up the displaying of images on the monitor making it possible to achieve effects not otherwise possible - for example, the presentation of very large images or of interactive games in which images need to change quickly in response to user input. Many new personal computers are now sold with a graphics accelerator built in. The power of a graphics accelerator can be extended further if the personal computer is equipped with the Accelerated Graphics Port ( AGP ), a bus (data path) interface between the computer components involved in image display.

Each graphics accelerator provides an application program interface ( API ). Some support more than one API. Among the most popular API's are the industry standard OpenGL and Microsoft's DirectX and Direct3D.

A type of video adapter that contains its own processor to boost performance levels. These processors are specialized for computing graphical transformations, so they achieve better results than the general-purpose CPU used by the computer. In addition, they free up the computer's CPU to execute other commands while the graphics accelerator is handling graphics computations.

The popularity of graphical applications, and especially multimedia applications, has made graphics accelerators not only a common enhancement, but a necessity. Most computer manufacturers now bundle a graphics accelerator with their mid-range and high-end systems.

Aside from the graphics processor used, the other characteristics that differentiate graphics accelerators are:

• Memory : Graphics accelerators have their own memory, which is reserved for storing graphical representations. The amount of memory determines how much resolution and how many colors can be displayed. Some accelerators use conventional DRAM, but others use a special type of video RAM (VRAM), which enables both the video circuitry and the processor to simultaneously access the memory.
• Bus : Each graphics accelerator is designed for a particular type of video bus. As of 1995, most are designed for the PCI bus.
• Register width: The wider the register, the more data the processor can manipulate with each instruction. 64-bit accelerators are already becoming common, and we can expect 128-bit accelerators in the near future