| The is a vital performance component of your | | | | introducing visual effects like multi-layered |
| computer, particularly if you play 3D games, | | | | shadows, reflection and fog.Fill rateThis is |
| or work with graphics and video content. The | | | | the speed at an image can be rendered or |
| graphics card sits in an expansion card slot | | | | "painted". This rate is specified in texels |
| in your PC and it is specifically designed to | | | | per second, the number of 3D pixels that can |
| process image data and output it to your | | | | be painted per second. A texel is a pixel |
| monitor, enabling you to see it. A graphics | | | | with depth (3D). The fill rate comes from the |
| card works by calculating how images appear, | | | | combined performance of the clock speed of |
| particularly 3D images, and renders them to | | | | the processor and the number of pixels it can |
| the screen. 3D images and video images take a | | | | process per clock cycle, and will tell you |
| lot of processing capacity, and many graphics | | | | how quickly an image can be fully rendered on |
| processors are complex, require fans to cool | | | | screen.Vertices/trianglesGraphics chips don't |
| them and need direct power supply. The | | | | work on curves, rather they process flat |
| graphics card consists of a graphics | | | | surfaces. A curve is created by multiple flat |
| processor, a memory chip for graphics | | | | planes arranged to look like a curve. 3D |
| operations, and a RAMDAC for display output. | | | | objects are created with multiple triangular |
| It may also include video capture, TV output | | | | surfaces, sometimes hundreds or even |
| and SLI and other functions. You can find the | | | | thousands, tessellated to represent the |
| graphics card that suits you by comparing | | | | curves and angles of the real world. 3D |
| specification between brands and vendors on | | | | artists are concerned with the number of |
| auAt au you can compare a great range of | | | | polygons required to form a shape. There are |
| appliances, and assess them according to | | | | two different types of specification: |
| their specifications, brands, prices and | | | | vertices per second (I.e., angles the |
| vendors.What are your needs?The first | | | | triangles), and triangles per second. To |
| decision you need to make is whether you need | | | | compare one measure with the other, you have |
| a graphics card for handling 3D images or | | | | to take into account the fact that adjacent |
| whether you are simply requiring 2D image | | | | triangles share vertices.Anti-aliasingA |
| rendering. For 2D requirements, you need only | | | | technique used to smooth images by reducing |
| a low-cost solution. In many cases, an | | | | the jagged stepping effect caused by diagonal |
| integrated graphics solution will suffice for | | | | lines and square pixels. Different levels of |
| 2D applications.However with 3D graphics, the | | | | anti-aliasing have different effects on |
| performance of the graphics card will impact | | | | performance.RAMDACThe Random Access Memory |
| directly on the frame rate and image quality | | | | Digital to Analogue Converter takes the image |
| of 3D programs and games. The differences | | | | data and converts it to a format that your |
| between the low and high-end cards can be | | | | screen can use. A faster RAMDAC means that |
| substantial, both in cost and | | | | the graphics card can support higher output |
| performance.Rendering 3D graphics is like | | | | resolutions. Some cards have multiple RAMDACs |
| lighting a stage, both the geometry of the | | | | allowing that card to support multiple |
| shapes in question and the lighting of it | | | | displays.TV-outSome graphics cards provide |
| need to be taken into account. The geometry | | | | the option to connect a television via either |
| of an image calculates the parts of an object | | | | a composite (RCA) or S-Video |
| that can and can't be seen, the position of | | | | connector.DVISome graphics cards include a |
| the eye and its perspective. The lighting is | | | | connector for DVI monitors, handy because a |
| a calculation of the direction of the light | | | | lot of LCD screens support DVI. DVI offers |
| sources, their intensities and the respective | | | | better image quality than the standard VGA |
| shadows that occur. The second part to | | | | connector.Dual-headDual-head is a term used |
| presenting a 3D image is the rendering of | | | | when two monitors are used side by side, |
| colours and textures to the surfaces of the | | | | stretching your desktop across both.SLI |
| objects, and modifying them according to | | | | (Scalable Link Interface.)With SLI you can |
| light and other factors.Most modern graphics | | | | couple two graphics cards in your computer, |
| cards include a small microchip called the | | | | enabling each card to take half the rendering |
| Graphics Processing Unit (GPU), which are | | | | thereby doubling the performance.When |
| provide the algorithms and memory to process | | | | considering your graphics card, it pays to |
| complex images. They reduce the workload of | | | | think about how much you need your computer |
| the main CPU, and provide faster processing. | | | | to process your graphics output. Using a high |
| Different graphics cards have different | | | | end graphics card with a high pixels per |
| capabilities in terms of processing power. | | | | clock rating, large memory, fast processor |
| They can render and refresh images up to 60 | | | | and other features means that you can run the |
| or more times per second, calculate shadows | | | | latest games efficiently, or work in |
| quickly, create image depth by rendering | | | | intensive graphics development.Different |
| distant objects at low resolution, modify | | | | ModelsWhile there are many vendors of |
| surface textures fluidly and eliminate | | | | graphics cards, there are actually only two |
| pixelation.What Specifications to | | | | major manufacturers of chips for graphics |
| ConsiderProcessor clock speedThis impacts on | | | | cards. Nearly every graphics card on the |
| the rendering capability of the GRU. The | | | | market features a chip manufactured by either |
| clock speed itself is not the critical | | | | ATI or Nvidia. Cards using the same graphics |
| factor. Rather it is the per-clock | | | | chip will perform roughly the same as each |
| performance of the graphics processor, which | | | | other. However, even though they use the same |
| is indicated by the number of pixels it can | | | | chip, some feature slightly higher clock |
| process per clock cycle.Memory sizeThis is | | | | speeds, as well as manufacturer guaranteed |
| the memory capacity that is used exclusively | | | | overclocking-an even higher clock speed than |
| for graphics operations, and can be as much | | | | that specified. Other factors that will |
| as 512MB. The more demanding your graphics | | | | influence your decision should include the |
| applications are, the better you will be | | | | amount of memory a card has (128MB, 256MB, |
| served with more memory on your graphics | | | | 512MB) and its additional features, such as |
| card.One thing that can slow down 3D graphics | | | | TV-Out and dual-screen support.Use the search |
| performance is the speed at which the | | | | facilities at au to compare the features, |
| computer delivers information to the graphics | | | | prices and vendors of graphics cards.Andrew |
| processor. A higher bandwidth means a faster | | | | Gates for comparison online shopping service |
| data transfer, resulting in faster rendering | | | | au. au helps you compare the different |
| speeds.Shader modelDirectX Shader Models | | | | graphics card from different brands in terms |
| allows developers control over the appearance | | | | of specifications and accessories. |
| of an image as it is rendered on screen, | | | | |