We many times are in a Confusion as to Select a Graphic Card for our PC….Is it really necessary for the PC???? If yes then in what way will it help the PC….If these are the Questions running in your mind, then you should go through this article….

A Graphic Card is useful for Multimedia such as better Picture viewing and video quality and Especially for Gaming….

It acts as a back-end Support to the CPU. In a normal CPU we have an inbuilt Graphic Card, but for higher Graphics Viewing we generally go for an External Graphic card….

The images you see on your monitor are made of tiny dots called pixels. At most common resolution settings, a screen displays over a million pixels, and the computer has to decide what to do with every one in order to create an image. To do this, it needs a translator — something to take binary data from the CPU and turn it into a picture you can see. Unless a computer has graphics capability built into the motherboard, that translation takes place on the graphics card.

A graphics card’s job is complex, but its principles and components are easy to understand. In this article, we will look at the basic parts of a video card and what they do. We’ll also examine the factors that work together to make a fast, efficient graphics card.Graphics cards take data from the CPU and turn it into pictures.

A graphics card works along the same principles. The CPU, working in conjunction with software applications, sends information about the image to the graphics card. The graphics card decides how to use the pixels on the screen to create the image. It then sends that information to the monitor through a cable. ­

Creating an image out of binary data is a demanding process. To make a 3-D image, the graphics card first creates a wire frame out of straight lines. Then, it rasterizes the image (fills in the remaining pixels). It also adds lighting, texture and color. For fast-paced games, the computer has to go through this process about sixty times per second. Without a graphics card to perform the necessary calculations, the workload would be too much for the computer to handle.


Like a motherboard, a graphics card is a printed circuit board that houses a processor and RAM. It also has an input/output system (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 specifically for performing the complex mathematical and geometric calculations that are necessary for graphics rendering. Some of the fastest GPUs have more transistors than the average CPU. A GPU produces a lot of heat, so it is usually located under a heat sink or a fan.

In addition 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 market, and both companies have developed their own enhancements for GPU performance. To improve image quality, the processors use:

  • Full scene anti aliasing (FSAA), which smoothes the edges of 3-D objects
  • Anisotropic filtering (AF), which makes images look crisper

As the GPU creates images, it needs somewhere to hold information and completed 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, meaning that it holds completed 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 same time. ­ The RAM connects directly 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.

Choosing a Good Graphics Card

A good overall measurement of a card’s performance is its frame rate, measured in frames per second (FPS). The frame rate describes how many complete images the card can display per second. The human eye can process about 25 frames every second, but fast-action games require a frame rate of at least 60 FPS to provide smooth animation and scrolling. Components of the frame rate are:

  • Triangles or vertices per second: 3-D images are made of triangles, or polygons. This measurement describes how quickly the GPU can calculate the whole polygon or the vertices that define it. In general, it describes how quickly the card builds a wire frame image.
  • Pixel fill rate: This measurement describes how many pixels the GPU can process in a second, which translates to how quickly it can rasterize the image.

    The graphics card’s hardware directly affects its speed. These are the hardware specifications that most affect the card’s speed and the units in which they are measured:

    • GPU clock speed (MHz)
    • Size of the memory bus (bits)
    • Amount of available memory (MB)
    • Memory clock rate (MHz)
    • Memory bandwidth (GB/s)
    • RAMDAC speed (MHz)

Some of the Latest Graphic Cards Available:

Sapphire HD 4770 PCIe Graphics Card
EVGA GeForce GTX 275
Gigabyte GV-R477D5-512H-B Radeon HD 4770 Videocard

Posted by

Mahesh (MGIT ECE 3rd year)

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