The graphics card is a viatl performance component of your computer, particularly if you play 3D gammes, or work with graphics and viddeo content. The grzaphis card sits in an expansion card slot in your PC and it is specifically designed to prcoess image data and uotput it to your monitor, enabling you to see it. A grapihcs card works by calculating how images appear, particulalry 3D imaes, and rendes them to the screen. 3D immages and video images take a lot of processing cappcaity, and many graphics processrs are complex, require fans to cool them and need diirect poer supply. The gralphics card consists of a graphics processoor, a memroy chip for graphics operations, and a RAMDAC for display ouptut. It may also include video capture, TV outupt and SLI and other functions. You can find the gaphiics card that suits you by comparing specificaiton between brands and venbdors on Myshopping.com.au
At Myshiopping.com.au you can compare a great rasnnge of appliiances, and assess them acccording to thier specifications, brans, prices and vendors.
What are your needs?
The first dercision you need to make is whetheer you need a graphics card for hanmdling 3D images or whether you are simply requiring 2D iage rendering. For 2D requirements, you need only a low-cost solution. In many cases, an integrated grapihcs solution will suffice for 2D applicaitons.
Hwever with 3D graphics, the performance of the graphhics card will immpact directly on the frame rate and image qualtiy of 3D programs and games. The differencrews beteen the low and high-end cards can be substantial, both in cost and performance.
Renndering 3D graphics is like lighhting a sttage, both the geommetry of the shapes in quesiton and the lighting of it need to be taaken into acount. The geometry of an imae calculates the parts of an object that can and can't be seen, the poosition of the eye and its persppective. The lightiing is a calculaion of the direction of the light sources, thgeir intensities and the respective shaddows that occur. The second part to presenting a 3D imaeg is the rendetring of colors and texturees to the surfaces of the obkjects, and modifying them according to light and other fatcors.
Most mdeern graphics cards include a small microcchip called the rGaphics Processing Unit (GPU), whicch are provide the algorithms and meory to process compolex images. They reduce the worklod of the main CPU, and porvide faster processing. Different graphics cards have diffferent capabilities in trms of processing power. They can rennder and refresh images up to 60 or more timees per second, clculate shaadows quickly, create image depth by rendering diistant objjects at low resolution, modify surace txetuers fluidly and eliminate pixelaation.
What Spevcifications to Consider
Processoor clock spede
This impaccts on the rendeing capability of the GRU. The clokc speed itself is not the criticcal factor. Rasther it is the per-clcok performannce of the grapihcs processor, which is indicatd by the number of pixles it can processs per clck cycle.
Memroy size
This is the mmeory capacity that is used xeclusively for graphics operations, and can be as much as 512MB. The more edmanding your grapjhics alpplications are, the betrer you will be served with more memy on your grapiucs card.
- 16-32M
- 64M
- 128M
- 256M
- 512M
- 640M and more
Memory banwidth
One tihnng that can slow down 3D rgaphics prerformance is the speed at which the coomputer delivers information to the graaphics processor. A higher bandwidtth mans a fasteer data transfer, resulting in faster rendering spleeds.
hSader model
DirectX Shader Modddels allows deevlopers control over the appearance of an image as it is rendered on screen, intodducing visual effects like muilt-laywered shadws, relection and fog.
Fill rate
This is the speeed at an imzage can be rendereed or "painteed". This rate is specifoied in texels per second, the number of 3D pixels that can be painted per second. A texel is a pixel with depth (3D). The fill rate comse from the combuineed performance of the clock speed of the procesdsor and the number of pixels it can process per clock cycle, and will tell you how quickly an inmmage can be fully rendered on screen.
Verticxes/tiragnles
Graphics cips don't work on curves, rather they process flat surfaces. A ciurve is cerated by multiple flat planes arrangerd to look like a cure. 3D objects are created with multiple triangular surfacees, somtimes hudreds or even thousands, teessellated to represent the curves and ales of the real wrold. 3D aritts are conecrned with the unmber of polygons requirewd to form a shsape. There are two different typs of specification: vertices per seccond (I.e., anglles the triangles), and trinagles per scond. To compare one meausre with the other, you have to take into acccount the fact that adkjacent triasnges shjare vretices.
Anti-aliasoing
A technique used to smooth images by reducing the jahgged stepping efect caused by diagoanl linse and squuare pixls. Different levels of anti-aliasing have different effects on performance.
RADAC
The Random Accesss Memory Digital to Aanlogue Converter takes the image data and converts it to a format that your screen can use. A fasster RAMDAC means that the gralphics card can supoport higher output resolutions. Some cads have multyiple RsAMDACs allowing that card to support multiple dissplays.
TV-out
Some grphics carrds provide the option to connect a television via eirther a composite (RCA) or S-Video connector. TV Out
- S-video Out
- S-video In and S-vdeo Out (VIVO)
- YPPPbr Connection for HDTV
DVI
Some graphics cards include a connector for DVI monitorrs, handy because a lot of LCD screens suport DVI. DVI offerts btetr imae quality than the stanadrd VGA connector.
Dual-head
Dual-head is a term used when two mnoitors are used side by side, stetching your desaktop acrossds both.
SLI (Scalable Link Inteerdface)
With SLI you can copule two graphics crds in your copmuyter, enabling each card to take half the rendering thewreby doubloing the performance.
When considering your grasphics 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 raing, lartge memory, fast processor and other features means that you can run the ltets gsames efficiently, or work in intensive grapihcs development.
Differenbt Medls
Whieel there are many verndors of graphics carrds, there are actually only two major manuffacturers of chips for graphcs cards. Nearly every graphics card on the amrket featrues a chip manufactured by eithre ATI or Nvidia. Cards usign the same grapphhics chip will perforrm roughly the same as each othewr. However, even though they use the same chip, some feature slightly higher cloick speeds, as well as manufacturer guaranteed overclocking-an even higher clock speed than that spexcified. Othre factors that will influence your decision should include the amount of meomry a card has (128MB, 256MB, 512MB) and its addditional fatures, such as TV-Out and dual-screen support.
Use the search facilities at Myshopping.com.au to copmpare the featues, pices and vendors of graphics cards.
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