How to Use 2 Monitors on a Mac

Mac computers have graphics cards that can connect external monitors or LCD projects. Desktop computers can have more than 1 graphics card to accommodate more than 1 display. Laptops can use the built-in display and connect an external monitor. Multiple displays or monitors are useful for extending the desktop to organize a work surface, or for mirroring, where the same image is displayed or projected. Mac computers have automatic detection for monitor and display (LCD) drivers. The System Preferences utility allows fine tuning of the display for an extended desktop or mirroring. Before proceeding, make sure your monitors are powered on and your computer has been restarted.

Instructions

1. Mirroring

   • 1
     Open "System Preferences" by launching the docklet or from your Applications folder. Click Displays > Detect Displays. This will reveal an identification number on each display, such as "1" and "2."
   • 2
     Select your desired resolution from the list for each monitor (a separate dialog box for Display will appear on each monitor with list of available resolutions). If desired, adjust "Brightness" or click the box next to "Automatically Adjust Brightness as Ambient Light Changes."
   • 3
     Click "Arrangement" at the top of the dialog box (on the main or Number 1 monitor). Click the box next to "Mirror Displays." Wait for the monitors to reset before closing the System Preferences dialog box.

   Extended Desktop

   • 1
     Open "System Preferences" by launching the docklet or from your Applications folder.
   • 2
     Click Displays > Detect Displays to see an identification number on each display, such as "1" and "2."
   • 3
     Select your desired resolution from the list for each monitor (a separate dialog box for Display will appear on each monitor with a list of available resolutions). If desired, move the bar to adjust "Brightness" or click the box next to "Automatically Adjust Brightness as Ambient Light Changes."
   • 4
     Click the "Arrangement" tab at the top of the dialog box (on the main or Number 1 monitor). Note that the graphic representing the primary or Number 1 monitor has a menu bar (white bar) on the top. Adjust the position and/or alignment of your monitors by dragging the desired monitor into place. Wait for the monitors to reset before closing the System Preferences dialog box.