Presentation by David Fong Graphics Cards Presentation by David Fong

What are graphics cards used for? Animation Gaming – both PC and console Design/Drafting Special effects creation/editing Medical Instruments And other purposes where fast rendering and high resolutions are needed

History Over the years, more colors, higher resolution, faster bus interfaces, and more memory.

History Monochrome Display Adapter (MDA) was the first video card created in 1981 – displays green text on black screen Video Graphics Array (VGA) = very popular and was the standard in almost every PC up until recently First 3d video cards were released in 1995 and they used SVGA; learned to create 3d effects

Monochrome Monitor

Components Graphics Processing Unit (GPU): perform calculations for rendering and figure out what to do with each pixel Video Memory: storing images and information about each pixel Output: Common outputs include Video Graphics Array (VGA) for CRT monitors, Digital Visual Interface (DVI) for flat panel displays, and Video-in-video-out (ViVo) for television and video cameras

Components Heat sink and Fan: used to cool the GPU, just like the CPU of a computer having the same cooling instruments Motherboards: PCI before AGP Motherboards: Accelerated Graphics Port (AGP) compatible popular decade ago; Peripheral Component Interconnect Express (PCI-E) gaining popularity BIOS chip that stores settings, information about each component of the graphics cards, and can be altered for over-clocking

Picture of Graphics Card

How graphics cards work? Take data from CPU and figure out what to do with each pixel to create image Create wire frame using vectors Fill remaining pixels with color, lighting, and texture The filling will consider viewpoint For games and video, the graphics cards has to do the above steps for 30 frames per second

How graphics cards work? In greater detail: GPU creates image, stores image with location and color of each pixel in memory Memory also holds completed images until it’s time to display them (frame buffer) Digital-to-analog converter (DAC) is connected to memory and translates image into analog signals that is sent through monitor cable and the image is displayed on monitor

Wire image Draw 12 lines for cube, then fill in A curve is created by many short lines

3d Image Development

3d effect: Mip-Mapping Pre-calculated images of target image Target image, may have several copies which is ¼ the size of previous image Makes rendering faster when the output is moving toward and further away from a target image

3d effect: Z-buffering Each pixel is part of a 2d coordinate (x-y coordinates) Depth is z-coordinate When a new object that is rendered wants to take a pixel, Z-buffering checks which pixel is closer to the observer, the old pixel or the new pixel based on the z-coordinate If new pixel is closer, the new pixel is buffered and replaces old pixel

3d effect: Anti-aliasing When trying to represent high resolutions signal at lower resolutions. Smoothes out edges to the human eye by blending of colors

Anti-aliasing

Anti-aliasing

Anti-aliasing

Anti-Aliasing

Anti-Aliasing

Extra Features ATI and nVidia added enhancements to their GPUs including: Anti-aliasing which makes smoother edges for 3d objects Anisotropic filtering: creating crisper images Dual-monitor support which can increase productivity TV-tuner

Do you need a graphics card? If you only surf the web, watch streaming videos, chat, or word processing, the integrated graphics processor on your motherboard is enough. If you play games or work with 3d graphics, then a graphics card is recommended.

How to judge quality of graphics card? Most of the time, you can judge the quality of a graphics card by the processor speed and how much memory the card has. There are some sites that do benchmark tests (www.tomshardware.com) for comparable cards by running graphics intensive games or environments and measuring the frame rate (frames per second) Higher the frames per second, the smoother the transitions for frames in games and video

Manufacturers Intel: develop IGPs (integrated graphics processors) AMD (acquired ATI) develop GPUs Nvidia also develop GPUs Different manufacturers take GPUs and other components to assemble video cards; thus creating slight variations of video cards with same GPUs Video cards are marketed with GPU manufacturer’s brand name Most popular video brands are the Radeon of ATI and GeForce of Nvidia

IGPs vs Graphic Cards About 90% of computers use IGPs IGPs use the memory in the system instead of having dedicated video memory like Graphics Cards IGPs are way cheaper than Graphics Cards Performance always favors Graphics Cards Almost impossible to play high end games on IGPs

How much video memory you need? Depends on resolution and bits per pixel (how many colors possible for pixel) 32bpp = 2^32 = 4,294,967,296 colors Minimum memory = Resolution x bpp Example: 1024 x 768 x 32 bits per pixel 25,165,824 bits / (8 bits per byte) 3,145,728 bytes So need a little bit more than 3 MB of memory

Future Because of growing processor speeds, there may be a need to develop a faster way for the CPU to transfer bits to the GPU (like how AGP was needed a decade ago, and PCI-E few years ago) With greater GPU speeds, comes greater demand for power (a simple PCI-E connection is not enough to power a high quality graphics cards these days, most likely needs additional sockets to be connected for power) The growth in processor speed and memory will create higher fps at greater resolutions

Twix How to calculate the minimum amount of video memory you need?

Twix What was the most popular bus interface before PCI-E?

Twix How do most benchmark tests measure the performance of a graphics card?

Sources Howstuffworks.com Wikipedia.org Encarta.msn.com Brighthub.com Pcwize.com