Wednesday, December 10, 2008

A bit of stuff about graphics cards

A graphics card (also video card) is a piece of hardware installed in a computer that is responsible for rendering the image on the computer’s monitor or display screen. Graphics cards come in many varieties with varying features that allow for a price range that extends from about $20 US Dollars (USD) to $2,400 USD or more.

The first consideration when buying a graphics card is to be sure it is capable of displaying the best resolution the monitor can support. For Liquid Crystal Display (LCD) monitors this means supporting the native resolution. Cathode Ray Tube (CRT) monitors do not have a native resolution. In this case, ensure the graphics card is capable of supporting the highest resolution, even if the CRT monitor will be frequently used at lower resolutions.

The second consideration is on-board memory. A graphics card must work very hard to render images to the screen. Unlike text files, graphics images are much larger files consisting of great amounts of data that must be processed by the graphics or video card. A faster graphics card has its own resident memory chips to perform this function so as not to impinge upon the system’s random access memory (RAM). Less robust graphics cards have less resident memory and require sharing system RAM to process images.

This doesn’t necessarily mean that a graphics card with shared memory will be unsatisfactory, but much depends on the primary purpose of the computer and on the amount of system RAM present. More system RAM is better if it will be shared, but for gaming and multimedia enthusiasts, a graphics card with resident memory is a better choice. This is also true for those wishing to watch, work with or edit movies.

The graphics processing unit (GPU) is a chip akin to the computer processing unit (CPU). The GPU on the graphics card processes data in parallel lines called “pipelines.” The more pipelines a graphics card has, the faster it can process data. Some cards feature dual GPUs for additional performance. Other factors that play into performance include bus speed and the type of on-board memory the graphics card supports.

Because graphics cards work hard they generate heat. For this reason most high-performance video cards utilize built-in fans. Fans can be quiet or noisy, depending on the card model. High-performance fanless video cards are also available. These cards use heat syncs to pull heat away from the GPU. The advantage of a fanless graphics card is lack of noise; disadvantages include expense and a wider footprint that can take up two slots inside the computer.

Installing a graphics card is very easy. The card features an interface that plugs into a port or slot inside the computer on the motherboard. Older motherboards offer an Advanced Graphics Port (AGP) interface, while newer boards have the faster Peripheral Computer Interface Express (PCIe) interface. A PCIe graphics card cannot be installed into an AGP slot, and visa-versa, so be sure to get a card that is compatible with your system.

External ports on the graphics card can allow an additional monitor to be plugged in for gaming or for advanced graphics displays that can be spread across two monitors. A graphics card might also have an “S-Video Out” port for sending the signal to a television, or a High Definition Multimedia Interface (HDMI) port. Advanced ports that extend functionality add to the cost of the card.

While prices vary widely, the average gaming enthusiast is likely to be happy with a graphics card in the $150 - $300 USD range. For someone who uses a computer for more general purposes, a graphics card closer to $65 USD will likely do the job. Watch for rebates and sales to get a good deal, and read customer reviews for information about issues like fan noise and performance.

No comments: