How to Free Up Virtual Memory on a Mac
By Ellis Davidson
Macintosh OS X automatically maintains virtual memory for the user, and under normal operations you should not need to take any specific steps to free up virtual memory. However, after many applications have been opened, your Mac may slow down considerably when switching between them, so cleaning out virtual memory manually may improve performance. This is also useful before launching a single application that uses a lot of memory, such as those used for photo or video editing or high-definition playback.
Hold down the Command button and hit the Tab key. All currently open applications will appear in a stripe of icons across the center of your screen. Continue to hold the Command button, and tab to each application you are not using, then hit the “Q” key to quit it. The application tab bar will remain on the screen until you release the Command key. (This can also be done from the Dock, but the Command-Tab method is much faster.)
Select “Log Out” from the Apple menu to return to the log-in screen of your Macintosh. All currently running user applications will quit, but background processes on your Macintosh will continue. This will free up more memory than the individual application method in Step 1.
Restart your Macintosh from the Apple menu, or by pressing the Power button and clicking the Restart button. This will clear out all of your virtual memory and start your memory over from scratch when your Macintosh finishes restarting.
Ellis Davidson has been a self-employed Internet and technology consultant, entrepreneur and author since 1993. He has written a book about self-employment for recent college graduates and is a regular contributor to "Macworld" and the TidBITS technology newsletter. He is completing a book on self-employment options during a recession. Davidson holds a Bachelor of Arts in American civilization from the University of Pennsylvania.