Is Having More Than One Display Useful?

Why an external monitor can boost productivity and performance

Most laptops and desktop computers can run more than one display. A desktop display can be spanned across several external monitors or mirrored or cloned to appear on an external monitor.

Having one or several monitors expands your workspace. If you have a small laptop, an external monitor delivers improved image quality while simulating the externality of a desktop computer. Monitors are also used in presentations, allowing an audience to view a larger display than the primary one provides.

In this guide, we look at why having more than one monitor can be to your advantage.

Higher Resolution at Lower Cost

One reason for running multiple monitors is economic. While higher resolution displays have become cheaper, it is still somewhat costly to get very high-resolution displays. For instance, many 4K PC displays cost around $400 for a 3200x1800 resolution. That is four times the resolution of a single 1600x900 resolution display. It used to be cheaper to buy four small displays, each with 1920x1080 (HD) resolution, and tile the displays together for an image that is comparable to 4K. As 4K/UHD tech has become more affordable, that's no longer the case.

Network administrator using three computer monitors in a home office.
Laurence Dutton / Getty Images

What Is Needed to Run Multiple Monitors

To run multiple monitors on a computer, you need a graphics card with more than one video connector. A typical desktop motherboard features two or three video connectors, while a dedicated graphics card may have more than four. Some specialized graphics cards have up to six video connectors on a single card.

There are no software requirements to set this up, as Windows, macOS, and Linux can run these graphics cards. The restriction usually comes down to the hardware. Many integrated graphics solutions are limited to two displays. Many of the dedicated cards can go up to three without much of an issue.

Read the documentation for the graphics card, as it may require that the monitors run on specific video connectors such as DisplayPort, HDMI, Thunderbolt, or DVI. As a result, you must also have displays with the required connectors.

Spanning and Cloning

When a second monitor is connected to a computer, you are typically presented with two ways to configure the second screen. The first method is called spanning. This is where the computer's desktop displays across both screens. As the mouse moves off the edge of the screen, it appears on the other screen. Spanned monitors are typically placed above, below, or next to one another. Spanning increases the overall workspace, which helps when working with editing software, games, or applications that require multitasking. Displays can also be tiled across several displays.

Here are some cases where spanning may prove useful:

  • Multitasking: Host windows and applications on separate monitors, such as word processing on one and web browsing on the other.
  • Editing software: Keep a zoomed-out preview image on one screen while zooming in and editing on the second. This is especially helpful on content creation-focused machines like the MacBook.
  • Gaming: Expand the viewing space for games, or keep inventories and status windows within a dedicated monitor.

Cloning means that a second screen is used to duplicate what is seen on the source display. The most common usage of cloning is to give presentations through applications like PowerPoint. It lets the presenter focus on the primary screen while the audience watches what is happening on the second, presumably larger screen. Cloning is also useful when a laptop screen is too small for various creative tools or gaming rigs.

Drawbacks to Multiple Screens

While the economic cost of multiple screens is a bonus over a single larger screen, there are drawbacks to using multiple monitors. Desk space is a concern, especially with larger LCD monitors. For instance, three 24-inch displays can take over an entire desk, compared to a single 30-inch LCD. Tiling displays may require specialized mounts to properly hold the displays in place and not wobble or fall over. This decreases the economic benefits compared to using a higher resolution display.

Since the two screens are separated by the bezels surrounding each screen, users may be distracted by the empty space between the displays. This can make programs that span multiple screens a little awkward. Smaller bezel sizes combat this effect, but there is still some gap in the combined image. 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.

Finally, some applications don't use a secondary screen properly. The most common of these are old DVD applications. These applications tend to display the DVD video in an overlay. This overlay function only works on the primary screen. If the DVD window is moved to the secondary monitor, the window will be blank. There are a few models that support dual monitor applications, but most are in vehicles. This is less of an issue as DVD usage fades away in favor of streaming, but many PC games only run on a single display.

Should You Use Multiple Monitors?

You may appreciate an external monitor if you do a lot of multitasking that requires windows to be visible at all times or if you do editing work with graphics, video, or music software and require a dedicated preview window.

Gamers that want a more immersive environment will benefit. However, the extra displays have some serious hardware requirements to produce a fluid image at higher resolutions. The average person may get by fine with a standard 1080p resolution display. There are also affordable high-resolution displays that make having two displays less economical.