Computers:Graphics Card
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Introduction
The interface between your computer and monitor, the graphics card is an important component in any computer system. While it may not have a lot of effect on performance, the quality and connectivity options that it provides will be important factors to consider.
Impact on Performance
As counterintuitive as it may sound, video cards have little effect on the performance of most 2D imaging tasks. The advancements made in recent years have been almost exclusively focused on 3D performance, so conventional 2D tasks remain largely uneffected. As such, unless this capability is needed for other tasks a modest graphics card will generally be more than sufficient.
Core Image
The one major exception to the above is for users of Apple Macintosh computers. Recent versions of OS X have implemented a technology called Core Image that makes use of graphics hardware to offload some image processing tasks from the processor. Software that is programmed to take advantage of this (such as Aperture) will be reliant on the performance of the graphics card, so buying high-end offerings will be a significant boon to these users. Note that this will not have any effect on software not explicitly using this technology (eg Photoshop).
Multi-Monitor Capability
Available on the vast majority of modern graphics cards, the ability to attach more than one monitor to a graphics card can be a significant benefit. The added real-estate provided by a second monitor allows photographers to spend more time working and less time fidling with windows and tool boxes.
Connectivity
One major aspect that photographers should look closely at is connectivity provided by the video card that they select. While many cards have dual outputs, most of them only provide a single DVI output. This limits the choice of monitor configurations, so if at all possible it is often a good idea to look for cards offering two DVI outputs.
Dual-Link DVI
With the advent of extremely high resolution displays (such as the 30" offerings from Apple and Dell), conventional single-link DVI connections are not able to keep up. To remedy this problem, newer graphics cards are begining to offer dual-link outputs to drive these monitors. The nVidia 7000-series and ATI x1000-series cards all offer at least one dual-link card, with the higher-end cards offering two.
Look-Up Tables
Colour Look-Up Tables are an imporant facility offered by graphics cards for photographic workflows. This table allows the video card to perform some basic colour/gamma corrections on-the-fly and aides in the colour calibration process. Thankfully, pretty much all current graphics cards provide functional CLUTs so users generally don't have to concern themselves with this detail.
See Also
- PCI-E - Interface used to connect graphics cards to the main computer.
- DVI - An interface used to connect graphics cards with either digital or analog monitors.
- VGA - An interface used to connect graphics cards with analog monitors.
- Core Image - An API offered on modern Macintosh computers that allows software to make use of the GPU for image processing tasks.
