Mac OS X Enable Fast User Switching

Posted September 22, 2004 by macster in Mac system administration

Mac OS X is a UNIX-based operating system with all the cool bells and whistles. One of the biggest differences is that UNIX is a multiuser environment allowing multple users to be logged in at the same time. Mac OS X takes swapping between users to a funky new level with a feature called fast user switching. This feature is turned off by default. This tutorial explains how to turn it on.


To turn on fast user switching, open the System Preferences and click on the Accounts icon under the System category. Click on Login Options near the lower left and click the Enable fast user switching checkbox.

The menu bar at the top of the screen will change, inserting the current user name at the top right. When you click on this name, you will see a menu listing all of the system’s users and a Login Window… choice. Clicking on a user’s name will switch to that user (possibly after requesting a password). Clicking on the Login Window… option will take you to the login screen.

The fast user switch occurs with a dramatic rotation of the screen, a slick effect. Be warned that each user logged into a system eats up memory. The more applications open for each user, the more likely the system will swap stuff into virtual memory and system performance will suffer.

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