What Features to Look for When Buying a New Age Graphics Card

With the era of the mighty NVIDIA 8800 or later the mightier NVIDIA 9800 long gone, and with the advent of newer technologies, we are left with a dilemma. Which brand to choose? NVIDIA or ATI. What to buy? An older cheaper card that sucks more power or go for the newer eco-friendly models? What to put ahead? Raw power in terms of frame rates or power efficiency accompanied by a silent fan freeing you of the headaches. Like I said, we are left with a dilemma...

Why Am I Writing This Article

Let me clear a few things first. This article is meant to explain a few terms frequently associated with graphics cards. In no way I am going to suggest a card for you nor tell which one is better, NVIDIA or ATI. In fact, noone is better. At times ATI outperforms NVIDIA with some cool new manufacturing process that eases the power requirements, only to be outdone by an even better technology from NVIDIA in the next minute. You have to keep a watch for the best cards that hit the market, everyday.

1. What do you call a computer without a CPU?
2. And what do you call a graphics card without a GPU?

Well, the answer to both the questions above is the same. Useless.

People tend to look for more memory and completely ignore the GPU when buying their first graphics card. I know I did. My very first graphics card was a cheap NVIDIA 8400GS with 512MB of dedicated graphics memory . Was I happy with my card? Hell no! It was useless . Just because I put memory size over everything else and ignored the GPU, I ended up buying the wrong card.

It processes pixels.

Let me explain things a bit. Memory is a passive component of the graphics card, in a sense that it does not do anything at all by itself. On the other hand, GPU is the active component. There are a lot of things a GPU does.

1. When you start a game, it takes game level data from your hard disk and places them in your graphics memory. All this happens behind the curtain. In the meantime, you see a fancy bar that says game loading .
2. With the game data in place, the GPU continuously calculates pixel values based on the game data combined with some game logic and fills your monitor with the pixels. In other words, it draws frames, one frame at a time. Every time you change your place it draws new frames. That way you get the illusion that things are moving. How many times a GPU is able to draw a frame per second is known as the FPS or frames per second that you heard so much about.
3. Performs post-processing tasks that are discussed later.
   

Now you know that your FPS depends more on the GPU and much less on the memory size. To be honest, memory size affects your FPS only indirectly. I'll explain this when we'll discuss memory.

The next most important feature of a graphics card is its on-board memory size. I am referring to the amount of memory that comes with the card itself. Although some cards may also use system memory (RAM) alongside on-board memory, the performance is not the same. It is much harder and time-consuming for a GPU to get access to data that live in system memory. The reason is that RAM is under direct control of the CPU and graphics card's on-board memory is under direct control of the GPU. Your graphics card must ask for CPU's permission each time it takes data from the system memory.

You already know that the on-board memory is faster from the perspective of the GPU. Thus the more memory you have, the more amount of data can reside in it at the same time. That means your card will run out of memory less frequently resulting in smoother gameplay. Because each time your card runs out of memory, it must load new data from your hard disk (where you have installed the game) and put it in your card's memory.

Another important aspect maybe post-processing. Some advanced effects used in today's games may require two or more copies of the same data to reside in your card's memory. Previous frames are preserved since rendering logic depends on the previous frames also.

Post-processing Examples

• Depth of Field - Blur landscapes in the distance or close up like Camera Out of Focus.
• Motion Blur - Blurs screen movement to give games a more "movie feel" during fast motion.
• HDR - High Dynamic Range Lighting - Lighting of environment changes according to were the camera view is (Inside/Outside).
• Colour Correction and Clamping - Seems to limit the range of colours to give a more realistic feel or washed out feel.
  

Though less important but definitely not a feature to overlook is your card's DirectX support. If your favourite game requires DirectX 10 but you buy a DirectX 9.0c card, your game simply will not run. With the arrival of DirectX 11 with Windows 7, you should look for at least DX11 support on your cards. OpenGL support is less important for games though.