Use these multi-monitor options to customize your Mac experience

Many users are opting for multiple screens to increase productivity. Here are some best practices for using external monitors with your Mac.

Image: Sarah Tew/CNET

One of the single most frustrating aspects of working on a computer is balancing screen real estate to support your most important applications and tools. Sure, there are shortcuts you can use to quickly switch between windows and tabs, but it's often easier to just have more space.

For many people, using multiple monitors is an easy solution that instantly provides more room. The use of additional monitors has also been bolstered by the growing trend of laptops replacing desktops in the enterprise, giving users a bigger screen without sacrificing the portability of the machine.

Mac users have a plethora of options when it comes to using an additional screen. Here are some of the ways to make it happen.

Selecting your display

Before you begin to think about how you'll use the additional screen space on your new monitor, you'll want to figure out how you're going to connect it to your machine. Most modern Macs will have one or two Thunderbolt ports, and sometimes will have an HDMI port as well. Your first choice is to determine how you want to send your signal out of your machine.

If you're running a device with one Thunderbolt port, such as a MacBook Air, you can only use that port. But, if you have a machine with both a Thunderbolt and an HDMI port, you do have to choose.

Thunderbolt is a great option for display out, but you really only get the full experience if you are using a Thunderbolt display made by Apple. Thunderbolt supports audio, video, and data, so it will automatically push the sound to the speakers on the Thunderbolt display. Two displays can be daisy-chained together to give you three full screens with minimal effort. Using a Thunderbolt display with your Mac will require no extra cable purchases or adapters, as the Thunderbolt cable is included with the display.

If you decide to use your Thunderbolt port with a third-party monitor, you will need to purchase an adapter and a cable. The Thunderbolt port doubles as a Mini DisplayPort, so you'll want to look for a Mini DisplayPort adapter to convert to the type of connection used by your third-party display. Common examples include Mini DisplayPort-to-VGA, Mini DisplayPort-to-HDMI, and Mini DisplayPort-to-DVI. Keep in mind that some displays will actually come with an adapter as well.

However, many users decide to go with HDMI to free up their Thunderbolt ports for expansion opportunities through external hard drives or other peripheral devices. If you decide to go with HDMI, you can run a straight HDMI cable into a display that accepts HDMI, or you may need to find an HDMI adapter for another kind of display.

You can also set up an iMac to run as an external display for another Mac using Thunderbolt or Mini DisplayPort by enabling what is known as "Target Mode." Connect the two machines via a Thunderbolt cable if they both have Thunderbolt ports, or with a Mini DisplayPort to Mini DisplayPort cable if one or both only have a Mini DisplayPort.

Once you have both machines connected, turned on, and awake, press Command+F2 on the keyboard of the iMac that you want to act as an external display. This should put it in target mode and make it selectable as an external display.

Setting it all up

Once you have your monitors connected to your machine and everything is powered up, you need to set up your display to operate the way you want it to. The first option, which primarily works for MacBook users, is to "push" your existing desktop to the display. To accomplish this, you'll need to close the lid on your MacBook while connected to the external display and it will show up, exactly as it was, on your external display. Just make sure you have a bluetooth keyboard and mouse connected to your machine beforehand.

Perhaps the most popular option is to run your extra display as an extended desktop. Basically, what this means is that the new screen will operate as a continuous part of your existing desktop. You are just adding new space to work on. To start, begin by clicking your grey "System Preferences" icon in your dock.

Once inside the System Preferences, you should locate and click the "Displays" icon.


Under the Displays tab, you'll be able to change the settings on your current display and change the way your external display is set up. Click the "Arrangement" tab at the top of the window to access the options for customizing your display as an extended desktop.


Start by making sure that the box next to "Mirror Displays" is unchecked, as that will force your Mac to see your external monitor as part of an extended desktop. In the middle of the window, you should notice two or more blue boxes, representing the number of screens you have connected.

The smaller screen with the white bar at the top represents the screen of your machine itself, whether that be a MacBook or Mac desktop machine. From this point, you can click and drag the boxes to represent how your extended desktop will extend across the screens. For example, if you put the machine screen at the top right of the monitor, you'll be able to move your mouse off of the right side of your machine screen and onto the external monitor.

Move it wherever you like and give your machine a minute to calibrate.


Now, if all you want to do is copy the desktop on your machine onto your external monitor, you should click the check-box next to "Mirror Displays" to make that happen. That means your external monitor will display an exact copy of what you're seeing on your machine desktop.


External monitors can be very useful tools for Apple users in the enterprise. Hopefully this gives you the resources you need to expand your screen real estate and get more work done.

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About Conner Forrest

Conner Forrest is a Senior Editor for TechRepublic. He covers enterprise technology and is interested in the convergence of tech and culture.

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