Introduction
Many graphics cards sold on the market today have the ability to run multiple monitors. The question is, what is the purpose of running multiple monitors from a single computer? After all, wouldn't it be cheaper to just produce graphics cards that run a single monitor instead of the extra circuitry for multiple displays? The majority of people who use a computer only use a single display. So just what exactly is the point of this feature?
Same Resolution, Half the Price
The main reason for running multiple monitors is economic. It is extremely expensive to produce LCD panels or cathode ray tubes with very high resolution graphics. For example, the average 30” wide screen LCD monitor costs between $2,000 and $3,000. The resolution for such a monitor is typically 2560x1600 and requires a special video card that supports the DVI-D dual link connector. Now compare that to purchasing two 20” LCD displays that have a resolution of 1600x1200 each and cost between $500 and $600. Those two monitors would provide a total of 3200x1200 of graphic workspace for roughly half the cost of the same 30” screen.
What is Needed to Run Multiple Monitors
There are really only two things required to run multiple monitors on today's modern PCs. The first is either a graphics card that has two monitor ports or two graphics cards inside of a computer system. And of course, you will also need all of the monitors that you wish to hook up to the computer as well. No special software is really required as all of the major operating systems including Windows, Mac OS X and Linux can support multiple graphics cards and monitors. Some graphics cards may come with some additional software to run that expand upon the basic spanning and cloning features found in the operating systems.
Spanning and Cloning
Since I just mentioned these two terms, let me explain what they mean. When a second monitor is attached to a computer, the user is typically presented with two ways to configure the second screen. The first and most common method is called spanning. This is where the computers desktop will be displayed across both screens. As the mouse is moved off the right side of the left screen, it will appear on the left side of the right screen. Spanning increases the overall workspace that a user can run applications. Common spanning applications include:
- Multitasking applications on separate monitors (Web on one, email on other)
- Graphics image preview on one screen and zoomed editing in second
- Extended viewing space for simulation games (Flight Simulator)
Cloning on the other hand means that a second screen is used to duplicate what is seen on the first screen. The most common usage of cloning is for individuals who are giving presentations through applications such as Power Point. This lets the presenter focus on the primary smaller screen while the audience can watch what is happening on the second screen.
Drawbacks to Multiple Screens
While the economic cost of multiple screens is definitely a bonus over a single larger screen, there are drawbacks to using multiple monitors. Desk space is not as big of an issue as it was when CRTs were in use. LCD panels are very thin and the overall space difference between a single 30” widescreen LCD and two 20” LCDs is much smaller than say a single 24” CRT versus two 17” CRTs. Still, with the limited space on most computer desktops or cubicles, even a few inches of wasted space can make a huge difference.
Since the two screens are separated by the physical spacing of the two screens, users can often be distracted by the empty space that resides between the two screens. This makes programs that span both screens to be quite distracting. This isn't the problem with a single large screen but is something to deal with on multiple monitors. Because of this, most people have a primary and secondary screen. The primary sits directly in front with the secondary either to the left or right and runs less used applications.
Finally, there are some applications that will fail to properly use a secondary screen. The most common of these are software DVD applications. They tend to display the DVD video in something called an “overlay”. This overlay function will only function on the primary screen. If the DVD window is moved over to the secondary monitor, the window will be blank. Most PC games also will only run on a single display failing to use any additional monitors.
Conclusions
So, should you use multiple monitors? The answer really depends on how you use the computer. Those doing a large amount of multitasking that require the windows to be visible at all times or do graphics and require a preview windows while they are working will. The average consumer doesn't really need this ability as they use only one or two applications at a time and do not need the additional workspace.
