- 2D or 3D: that is the question
- PCIe or AGP
- Graphics card models
- ATI cards
- ATI variations
- Nvidia cards
- Nvidia variations
- What the specs mean
- Other features
- Other components
- Power usage
- Integrated graphics
Much like washing powder companies, graphics chip vendors are rather inclined to throw technobabble at users about new and unique technologies in their products. CineFX, SmoothVision, HyperZ and a host of other graphics technologies are detailed by Nvidia and ATI in their marketing materials. Some of these technologies do have a significant impact on the performance or visual quality of the display, or on the ability of the card to compress video streams, but others may be just marketing fluff.
TV-out - you may want the ability, via either a composite (RCA) or S-Video connector to display the output of the graphics cards on a TV screen. TV-output can be a bit iffy, especially on older cards, because of its low resolution, interlaced scan and poor pixel precision. Therefore, you should only use the TV-Out port if you want to watch video from your PC on a TV screen. For more on TV-out, we recommend taking a look at our Media Centre PC Buyer's Guide. ^link^
DVI - a graphics card with DVI has a connector for DVI monitors. This is handy as there is a large range of LCD screens that support DVI. DVI is a type of monitor connector that offers better image quality than the standard VGA connector. Graphics cards that have DVI connectors usually ship with a DVI to VGA adapter that allows you to plug in an analogue monitor cable.
Dual-head- now sported by many graphics cards, dual-head is the ability to use two monitors, usually side by side. Your desktop stretches across both monitors. Cards with more than one output often support dual-head, although the heads may not be symmetrical. For example, an ATI card might have both a VGA connector and a DVI connector. You can use them in a dual head configuration if you want to run two monitors side by side.
SLI - this stands for Scalable Link Interface. Currently only supported by Nvidia in some of its GeForce 6600 and 6800 chips, SLI allows you to run two graphics cards side by side in your PC. When processing geometry and rendering a scene, each card takes half the scene, theoretically doubling the performance of the graphics subsystem.
SLI only works on PCIe motherboards, and the motherboard must have at least two 16x PCIe slots. You also obviously need to buy two SLI-supporting graphics cards, and both cards must be identical.
Motherboards that support SLI are also a great investment if you want to use more than two monitors on the same computer. Because you have two graphics card slots, you are free to install any two PCIe graphics cards in these slots (they don't have to be identical or even have the same chipset) to take advantage of up to four monitors, assuming the cards you install have both VGA and DVI connectors (dual-head).
Whilst older graphics cards are capable of drawing all necessary power through the AGP or PCIe slot they sit in, many modern cards have powerful fans and GPUs that actually require a separate power connection. If you are purchasing a high powered video card such as Nvidia's 6800 range, be sure to check the power requirements beforehand. You will need a spare power connector to plug into the card, and a power supply strong enough to cope with the extra wattage.