Why your Mac isn't working as fast as it says it is—and how you can fix it

John Smith wrote in with a very interest set of queries about whether his Macs slow down when they’re left to complete a task. “Do you know why and whether there is a way to prevent it?”John noted a few different behaviors he’d observed:After enabling FileVault on an older Mac, the time noted for completion ballooned dramatically when he’d walk away and come back.
An animation program estimated completion time after about 5 or 10 percent was done, but on his return