Buying a graphic card? Read this first...

Seriously speaking, most of us don't know what we are buying when we first purchase a graphic card. Me myself, when heard about graphic card, the first thing flashed in my mind is we need it (the graphic card) to play games, so that all the animations will look smooth and crispy. The weirder the graphic card look, the more power we thought it is. This in theory basically right and it should make sense to novice when buying their first one, but its not quite true.

Information outside the box of the graphic card is essential for us to rate whether the card we are going to purchase is on par to what we need. It is worth to note first however that the basic functions of the graphic card is to derive an image from a stream of binary bits. This deriving process mathematically is so complex that if we put it to our CPU (processor attached to the mainboard) to process it, it will consume all our computer resources. Have you ever heard the word 'rendering', it refers to the deriving process and it was very customed to those specialized in animation industry. Sometime it may takes weeks just to render an image. That's to show how complex it is. Having a good graphic card saves these rendering time.

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:

1) 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.

2) 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/specification also directly affects its speed. For example, given a specification "GeForce 7950 GX2 SLI", the corresponding hardware stats are:

Graphic bus technology : PCI Express
GPU clock speed (MHz) : 1000 (500 per GPU)
Size of the memory bus (bits) : 512 Bit
Amount of available memory (MB) : 1GB (512 per GPU)
Memory clock rate (MHz) : 1200 (600 per GPU)
Memory bandwidth (GB/s) : 76.8 (dependent on bus technology, in this case PCIe)
RAMDAC speed (MHz) : 400
Pixel fill rate (Billion pixels/sec) : 24
Vertices per second (Billion) : 2

Source:http://www.nvidia.com/page/geforce_7950.html

*Scalable Link Interface (SLI) - A technology developed by NVIDIA for combining 2 or more Graphic Processing Unit(GPU) together for better performance.

So, when you want to buy one, ask the sales person about the graphic card in terms of the above specification so that you can know whether it gives value for what you paid. Keep in mind that the bigger the number(from the above stat) the better the GPU. Happy shopping..