Processor and Memory
Like a motherboard, a graphics card is a printed track board that houses a processor and RAM. It also has an input/output arrangement (BIOS) chip, which stores the card's settings and performs diagnostics on the memory, input and output at startup. A graphics card's processor, called a graphics processing unit (GPU), is similar to a computer's CPU. A GPU, however, is designed particularly for performing the complex algebraic and geometric calculations that are necessary for graphics rendering. Some of the greatest GPUs have more transistors than the average CPU. A GPU produces a lot of heat, so it is habitually located under a heat go down or a fan.
In adding together to its processing power, a GPU uses special programming to help it analyze and use data. ATI and NVIDIA produce the vast majority of GPUs on the marketplace, and both companies have developed their own enhancements for GPU performance. To improve image feature, the processors use
Each company has also developed specific techniques to help the GPU apply colors, shading, textures and patterns.
As the GPU creates images, it needs somewhere to hold information and complete pictures. It uses the card's RAM for this purpose, storing data about each pixel, its color and its location on the screen. Part of the RAM can also act as a frame buffer, denotation that it holds finished images until it is time to display them. Typically, video RAM operates at very high speeds and is dual ported, meaning that the system can read from it and write to it at the equal time.
The RAM connects straight to the digital-to-analog converter, called the DAC. This converter, also called the RAMDAC, translates the image into an analog signal that the monitor can use. Some cards have multiple RAMDACs, which can improve performance and support more than one monitor. You can learn more about this process in How Analog and Digital video recording Works.
Input and Output
Graphics cards connect to the computer from end to end the motherboard. The motherboard goods power to the card and lets it communicate with the CPU. Newer graphics cards repeatedly require more power than the motherboard can provide, so they also have a direct connection to the computer's power make available.
Connections to the motherboard are regularly through one of three interfaces:
" Peripheral module interconnect (PCI)
" Advanced graphics port (AGP)
" PCI Express (PCIe)
PCI Express is the newest of the three and provides the fastest transfer rates between the graphics card and the motherboard. PCIe also supports the use of two graphics cards in the same computer.
Most graphics cards have two monitor relatives. Often, one is a DVI connector, which supports LCD screens, and the other is a VGA connector, which supports CRT screens. Some graphics cards have two DVI connectors instead. But that doesn't rule out using a CRT screen; CRT screens can connect to DVI ports through an adapter.
Most people use no more than one of their two monitor connections. People who need to use two monitors can purchase a graphics card with dual head aptitude, which splits the display involving the two screens. A computer with two dual head, PCIe-enabled video cards could theoretically carry four monitors
.
In toting up to connections for the motherboard and monitor, some graphics cards include associations for:
" TV display: TV-out or S-video
" Analog video cameras: ViVo or video in/video out
" Digital cameras: FireWire or USB
several cards also incorporate TV tuners.
