Video card - components and features

   In this post I will talk about the components and features that make up a video card. A video card, as you may probably know, is a component used by computers or laptops to display information on a monitor. A video card can be integrated in the motherboard or CPU, or it can be dedicated (connected separately to a dedicated video slot). A onboard video card doesn't have dedicated video memory this is why it uses the computer RAM memory. Because of this feature, integrated graphics have low performance. Unlike on-board graphics, dedicated video cards have their own memory and a special designed video processor. Because of these two independent components, the system resources are less used. Motherboards include a video chipset that can be either a AMD or Intel. Amd chipset use Radeon graphics and Intel chipset use Intel graphics.
The key components and features of video cards are:
   The GPU (graphics processing unit) or VPU (visual processing unit) is a digital circuit integrated into the video card body and is used primary for 3D applications. The GPU processes information and sends it to and from the Video memory.
   The Video memory has two main features, the memory clock rate and the Bandwidth. I've taken the following table from Wikipedia:
http://en.wikipedia.org/wiki/Video_card
Memory clock rate(MHz) Bandwidth (GB/s)
DDR1         66 - 950           1.2 - 3.04
DDR2         533 - 1000       8.5 - 16G
DDR3         700 - 2400       5.6 - 156.6
GDDR4      2000 - 3600     128 - 200
GDDR5      900 - 5700       130 - 230
This table displays how the video memory clock rate and bandwidth evolved from DDR1 to GDDR5.
Modern video cards have sufficient memory to be used by the GPU. Usually a buyer first looks at the memory quantity, but remember that the most important component of a video card is the GPU. The GPU is responsible for the video card's 3D performance (used mainly in gaming). There are many types of the same GPU, this is why you should also look at the frequency. Choose between Cuda cores (nVIDIA) and stream processor (AMD) or between Crossfire (AMD) and Sli (AMD) technology.
   The memory Bus - the communication channel between the GPU and the video memory. This is used to send information between these two hardware components
   The output connectors are the ports used by external peripherals (such as a monitor) to connect to the video card. There are many types of connectors like HDMI, DVI or VGA and there are video cards that offer multiple display connectors.
   The cooling system, which is commonly composed of the heating fan and a radiator, is another important component because the GPU must remain in the temperature parameters all the time.
   The digital and analog resolution - this component specify the distinct pixels in each dimension that can be displayed. It is characterised by the number of pixels per width × height.
   Direct X and OpenGL compatibility - these are standard APIs used by video drivers to specify 2-D and 3-D image processing. These two types of APIs are composed of elements that specify how the video component is processed. The next tabel from http://www.cprogramming.com/tutorial/openglvsdirectx.html will display the differences between OpenGL and Direct X:

Feature:	OpenGL	DirectX
Vertex Blending	N/A	Yes
Multiple Operating Systems	Yes	No
Extension Mechanism	Yes	Yes
Development	Multiple member Board	Microsoft
Thorough Specification	Yes	No
Two-sided lighting	Yes	No
Volume Textures	Yes	No
Hardware independent Z-buffers	Yes	No
Accumulation buffers	Yes	No
Full-screen Antialiasing	Yes	Yes
Motion Blur	Yes	Yes
Depth of field	Yes	Yes
Stereo Rendering	Yes	No
Point-size/line-width attributes	Yes	No
Picking	Yes	No
Parametric curves and surfaces	Yes	No
Cache geometry	Display Lists	Vertex Buffers
System emulation	Hardware not present	Let app determine
Interface	Procedure calls	COM
Updates	Yearly	Yearly
Source Code	Sample	SDK Implementation

   The interface between the video card and the motherboard - this component has some features like width, clock rate and bandwidth. The next image will display how the video interface features evolved in time:

This table was taken from Wikipedia: http://en.wikipedia.org/wiki/Video_card
   Maybe the least important factor is the physical size but of course you should check it out just in case the video card doesn't fit your computer configuration. The parameters of the physical size are width, height and thickness.
   I've pointed out all the main components and features that make up a video card, leave a comment if you have any questions or if you have something more to add. Stay tuned for more to come, meanwhile enjoy your day.