Mac+Power+Basics

By Peter Stromberg, ICSD ITT

Mac power basics: There are basically 5 states a normally operating mac computer can be in: -normal use: The display and other components are all powered up and ready for use, like when a student is using it. Full power is being consumed. -display sleep: The display is black, touching the keyboard or mouse returns power to the display and normal use resumes. This saves a good amount of power. -computer sleep: The display is black and the RAM is suspended. Touching the keyboard mouse returns power to the display and RAM and normal use resumes. -safe sleep: After running out of power while the at “computer sleep” the macbook will enter safe sleep mode. The RAM is written to hard drive and the whole device is powered down. The white LED light in the front starts blinking, after reconnecting to power the device will need to be turned on. The RAM is then copied back from the hard drive and normal use resumes. This process can take a minute or two. -shut down: This computer is completed turned off and consumes no power. Closing the lid puts the computer to sleep (computer sleep) unless an external display is connected. There are inactivity periods defined in System Preferences->Energy Saver for both battery and power adapter use. Here the macbooks are set to put the display to sleep and then the computer to sleep after not being used for the defined period of time. You can check and adjust these settings yourself. We can also easily set these periods remotely with our management tools. If you’d like these settings changed on a lab please enter a snoopy with the relevant information. The putting the display to sleep saves a significant amount of power. Putting the computer to sleep saves even more. Shutting the computer down consumes no power! Lab power/login management: Lab machines will sleep according to the inactivity periods or when their lids are closed. It is a good idea to shut down the laptops at the end of each day and start them up again in the morning. In practice, if you just let them sleep over night some nights and do a full shutdown other nights its fine. Certainly before weekends or extended breaks they need to be shutdown. As long as they are getting shut down fairly regularly they should be fine. Elementary School Labs: In an elementary lab environment, since all the students share the same login (XX.student) you can safely leave the machines logged in throughout the day with the student account. If you’d like to set a lab up to automatically log in your schools student account when it restarts we can do that (enter a snoopy). If a staff member needs to use a machine from an elementary lab they should logout the student account sign-in with their own account.