How a Graphics Card Works - Page 2

The graphics card started life as a fairly simple accelerator for just a couple of basic functions in the 3D rendering process, leaving most of the real hard work to the CPU. In contrast to this, today's modern graphics cards are now almost more complex than a whole computer put together. However, rather than being a general purpose device (like the PC it's usually attached to), a graphics card is a 'computer' with a very specific purpose.

Graphics cards only have to complete one primary goal in their lives, and that's to generate an appropriate two-dimensional image on one or more screens (no matter how '3D' that game you're playing is, the device your viewing it on is two-dimensional and flat - the output of a graphics card will thus always be '2D', not '3D' as some might think).

This goal can range from the relatively undemanding task of displaying a little envelope icon in your system tray to tell you that 'you've got mail', all the way through to rendering the highly detailed skin texture of a creature that's currently biting your legs off in one of today's latest graphically demanding 3D games, such as Quake 4 or F.E.A.R

Reiterating the 'graphics card = mini PC' analogy, the most important components on a graphics card (where graphical performance is concerned), are its processor - called the 'GPU' (Graphical Processing Unit) - which performs calculations and executes instructions, and the memory, which stores 'work in progress'.

A modern graphics card with no heatsink, showing the GPU and memory chips. You can also see the video outputs on the left and the graphics interface at the bottom.

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Article Navigation:

• Introduction
• The Basics
• Engines, Their Drivers and A Little History
• Telling Your Buffers from Your Outputs
• Feeding the Frame Buffer
• Surface Colours and Maps
  • MIP Maps
  • Bump Mapping
• Lights, Camera, Action!
• On The Buses
  • Interfaces
• Shaders
• Pipelines
• The Rendering Process - An Overview
• Improving Image Quality - AA/AF/HDR
  • Antialiasing
  • Anisotropic Filtering
  • High Dynamic Range
• End Frame
  • Links