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Be aware that external backups are pretty fast but they still require time to run. Do not shut down your computer or interrupt the backups until they are done. The more frequently you run your backups, the faster each backup cycle will be.
On the Mac, Time Machine does backup your account files as well as your Mac OS system files and Applications. Windows backup only backs up your account files like Desktop, Documents, Videos, etc.
Crashplan
For Internet backup solutions like Crashplan, be aware that this solution only works as well as the speed and stability of your Internet connection. If the machine using Crashplan is always at MIT, then the performance should be pretty fast and stable. To properly manage expectations, user should be aware that backup over Internet is not as fast as external backup to local hard drive. Having said that, Crashplan does not backup applications or the OS of your computer. Just the files in Documents, Desktop, Videos, Music, and Photos.
But because most of our users do take their machines home with them, variability in the speed and stability of home internet access can delay a complete backup of all recently modified files with Crashplan. We have observed delays in the report of completion in Crashplan backups from between 2 and 4 days for most active Crashplan users.