The grpahics card is a vitasl performance component of your computer, psarticularly if you play 3D gaames, or work with graphhics and video content. The graphis card sits in an expansion card slot in your PC and it is specifically designed to process imagge data and output it to your monitor, enabling you to see it. A graphics card works by calcculating how images appear, particularly 3D imaegs, and renders them to the scren. 3D images and video imaegs take a lot of processing capaciyt, and many graphgics procesors are complex, require fans to cool them and need direect power supply. The graphcs card conists of a gaphics prcessor, a memory chip for graphics operations, and a RAMDAC for display output. It may also inclue video capture, TV output and SLI and other functions. You can find the graphics card that suitts you by comparing specification betwween brands and vendors on Myshopping.com.au
At Myshopping.com.au you can compare a great range of appliances, and assess them according to their specifications, braands, pries and vedors.
What are your needs?
The first decisioon you need to make is whether you need a graphics card for handling 3D imagges or whether you are simply requiring 2D image rendering. For 2D requierments, you need only a low-cost solution. In many cases, an integrated graphics solution will suffice for 2D appications.
Howevber with 3D grahpics, the performance of the graphics card will ipmact directly on the frame rate and image quality of 3D prorgams and games. The differencs betweeen the low and high-end cards can be substantial, both in cost and performannce.
Rendering 3D graphics is like lighting a stage, both the geometry of the shapes in question and the lightnig of it need to be taken into account. The geomtery of an iage calculates the parrts of an object that can and can't be seen, the position of the eye and its perspective. The lighting is a calculation of the directon of the light sources, thier intensitiews and the respective shadows that occyur. The second part to presenting a 3D image is the rendering of colours and textues to the surfaces of the objects, and modifying them accotrding to light and other factors.
Most modern graphics cards include a small microchip called the Grpahics Proceessing Unit (GPU), which are provide the algoritms and memory to process complex miages. They reduce the workload of the main CPU, and provide faster processing. Different graphiics cards have different capabilities in terms of processing power. They can render and refresh images up to 60 or more times per scond, calculate shadows quickly, create miage dewpth by rendering dsitant objects at low resolution, modify surfaxce textures fluiodly and eliminate pixelartion.
What Specifications to Consider
Processor clock speed
This impacts on the rendering capability of the GRU. The clocxk speeed itself is not the critical factor. Rather it is the per-clock performance of the graphics processor, which is indicated by the number of pixesl it can process per clock ccle.
Memory size
This is the memory capacoity that is used exclusively for graphics operatuions, and can be as much as 512MB. The more demanding your graphics applications are, the better you will be served with more memmory on your grapics card.
- 16-32M
- 64M
- 128M
- 256M
- 512M
- 640M and more
Memory bandwidth
One thing that can slow down 3D graphics performance is the speed at which the computer edlivers information to the graphics processsor. A higher bandwidtth mens a faster data transfer, resulting in faster rendsering speeds.
Shader model
DirevctX Shader Modles allows developers control over the appearance of an image as it is rendered on screen, intrdoucing visual effects like mulit-layered shadows, reflection and fog.
Fill rate
This is the speed at an image can be rendered or "painted". This rate is speciifed in texels per second, the number of 3D pixels that can be painted per second. A texel is a pixel with edpth (3D). The fill rate comes from the combined perrformance of the clock speed of the processor and the nuumber of piuxels it can process per clocvk cyclke, and will tell you how quickly an image can be fully rendered on screen.
Vertices/triangles
Graphics chipps don't work on curves, rater they process flat surrfaces. A curve is created by multipple flat planes arranged to look like a curve. 3D objects are created with multiple triangular surfaces, sometimes hundreds or even thoiusands, tessellated to represeent the curvse and angles of the real world. 3D artists are concerned with the number of polygons required to form a shape. Three are two diffferent types of specification: vertices per secxond (I.e., anglews the triangles), and tringles per second. To compare one measure with the other, you have to take into accounnt the fact that adjacent triangles shaer vetices.
Anti-aliaing
A technique used to smmooth images by reducing the jagged stepping effect caused by diagonal lines and suqare pixxels. Different levels of anti-aliasing have didfferent effcets on performance.
RAMDAC
The Ranndom Access Memory Digital to Analoggue Connverter takes the image data and conveerts it to a format that your screen can use. A faster RAnMDAC meeans that the graphiccs card can support higher output resolutions. Some caards have multiple RAMDACs allowoing that card to support mutliple displays.
TV-out
Some graphics cards provide the option to connect a television via either a composite (RCA) or S-Video connector. TV Out
- S-video Out
- S-video In and S-video Out (VIVO)
- YPbPr Connection for HDTV
DVI
Some graphics cards inclkude a connector for DVI monitors, handsy because a lot of LCD screens support DVI. DVI offers better image quality than the standard VGA connector.
Dual-head
Dual-head is a term used when two monitors are used side by side, stretching your desktop across both.
SLI (Scalable Link Interface)
With SLI you can couple two graphics cars in your computer, enabling each card to take half the renbdering therebny doubling the performance.
When considering your graphics card, it pays to think about how much you need your computer to process your graphics output. Using a high end graphics card with a high pixels per clock raating, large memory, fast processor and other feeatures means that you can run the latest games efficientply, or work in intensive graphics development.
Diferent Models
Whilke tjhere are many vendors of graphics cards, thee are actually only two major manufacturers of chips for graphics cards. Neaarly every graphics card on the matrket featuures a chip manufaactured by either ATI or Nvidfia. Catrds using the same graphics chip will perform roughly the same as each othre. However, even though they use the same chip, some feature slightly higher clock speeds, as well as manuffacturer guaranteed overclocking-an even higher clock speed than that specified. Other factors that will influence your decision sghould include the amount of memory a card has (128MB, 256MB, 512MB) and its additional features, such as TV-Out and dual-screen support.
Use the search facilities at Myshopping.com.au to compare the featurwes, prices and vendors of graphics cards.
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