The inbuilt video adapters of the motherboard are not sufficient if you want to run advanced games or multimedia applications on your PC. The inbuilt video adapter is a conventional video adapter and can carry out normal functions perfectly well. But if you are looking out for realistic rendering, higher resolutions or more colors than the use of 2D or 3D accelerator video adapters becomes a necessity. The video boards disable the onboard video adapters and fit into the expansion slot of the PC. This Article deals with conventional video adapters as well as the 2D and  3D video adapters and is particularly important if you are in the process of learning how to build a computer because you may be tempted to take the cheap approach which is to go with the on board option. 

Conventional 2D video adapters.

The following is a list of conventional 2D video adapters. The display adapters went on improving and could support higher resolutions and more colors. At first available as separate cards, they were later integrated into the motherboards.

By using the conventional 2D video adapters higher frames rates required for graphic intensive gaming and multimedia applications of today cannot be achieved. At higher screen resolutions and use of greater amount of colors, it is not possible to achieve high frame rates without slowing down the processor. The games and multimedia applications of today are so much advanced, that even the use of PCI bus does not result in improvements of speed.

2D Video accelerator boards.

Use of the 2D Accelerator video boards can solve the above problem. The 2D Accelerator board has a small dedicated microprocessor which takes over the computation jobs and relieves the CPU of processing the data. This increases the

frame rate, without loading the CPU.

Along with the onboard dedicated processor, there is an onboard graphics co-processor which takes up the functions of specialized mathematical calculations, and allows the CPU to attend to other functions.

The 2D video accelerator boards also have onboard video Ram (VRAM). The video RAM is faster than the Dram and the EDO Ram. This can store lot of graphics data on board, thus enabling higher frame rates, resolutions and colors.

3D Video accelerator boards.

Many graphics applications of today want to display realistic scenes and create 3D effect on the 2D screen. However, the millions of calculations involved in the realistic graphics displays puts more strain on the CPU and the internal memories.

The 3D video accelerator  cards address the needs of the high-end 3D graphics applications. The 3D graphics cards  makes use of the AGP bus or the PCIe –x16 bus, which are wider and faster than the PCI bus.

In case of 3D video accelerator cards speed is the main factor as higher frame rates create realism and true-to-life atmospheres in 3D games and other 3D applications. The 3D accelerators have onboard video memory and GPU or ASIC (dedicated microprocessor chip) to achieve the higher resolutions and more amounts of colors. 3D geometry and rendering tasks are carried out by the ASIC, relieving the CPU of the task of performing the calculations. The use of higher-end buses makes possible fast operations, since the transfer of data between the adapter and the PC can take place at a faster rate.

Many of the 3D functions are incorporated as hardware functions and these tasks are performed by the graphics processor (GPU) on the 3D video accelerator card itself.  The 3D accelerator video card has support for the following :

1. Perspective corrections
2. Lighting effects
3. Texture transparency
4. Palietized textures
5. Texture mapping
6. Fogging
7. Alpha – bending
8. Gouraud shading
9. Double buffering and
10. Color dithering.

If a game or any application requires any of the above named support and the video card does not have it, the game or the application will either not run or run very slowly.

The two main companies producing 3D video cards are the NVIDIA and the ATI. The  NVIDIA  GeForce 7600 GT is older model of  3D video card produced by NVIDIA , whereas NVIDIA GeForce 8600 GTS is a new model. These video cards have onboard memory and GPU and provide high frame rates of around 30 FPS. The processor requires cooling and separate power supply connection. The video cards use the PCIe – x16 bus. Although the older model is good enough, the new model gives very good 3D performance and can be used for serious gaming applications.