The “Optimizing Your Mac” Notification in OS X Explained
Some Mac users may see a notification alert pop-up from OS X in the corner of their display with a message stating “Optimizing Your Mac – Performance and battery life may be affected until completed.” While there aren’t any additional details offered in the notification, there is a “Close” button, which will dismiss the alert. Typically this optimizing message appears after a system software update has installed, logging in to a new user account, or if the Mac has been rebooted after a long period of not being restarted. So, if you see this alert message, what’s going on and what should you do?
The answer is simple; do nothing, let the optimization process complete on the Mac.
The optimizing process can take a few minutes to a few hours, depending on a variety of things, including speed of the computer and drive, and what tasks are being performed. And yes, as the notification mentions, the Mac may be running slow as a result of the tasks going on behind the scenes in OS X.
For those that are curious about what exactly is going on when this alert message comes up, the specific processes can vary as can the functions, but often you’ll find it’s one or more of the following:
- The permissions repair process repair_packages
- Spotlight related processes indexing the drive, including index agent, mds, mdworker, or related processes indexing a drive
- iCloud Photo Library, photolibraryd, or Photos app completing a migration
- Various other system level functions or processes, whether find, makewhatis, ac, kernel_task, amongst others
Each of these will be going in the background and you’re free to use the Mac as the task completes, but as the alert says some things may be a bit slow or battery life may be temporarily reduced as this occurs.
If you want specifics, the easiest way to see exactly what is going on during this “optimizing your Mac” process is by going into the Activity Monitor application and sorting by CPU or by Energy usage, as long as you show processes by all users and system, you should quickly be able to see what exactly is going on. But whatever you do, don’t quit the process that is in use, you do not want to halt the optimization process mid-task as it will either just run again from the beginning, or could potentially cause a problem with whatever it is attempting to do.
This alert dialog is visible in many modern versions of OS X though many users will never see it at all, though it seems to appear most often after updating system software to a new point release, or going to an entirely new release version (say from Mavericks to OS X El Capitan).
If you have any added details to offer about the “Optimizing Your Mac” message, or perhaps you know how to trigger it manually, do share, or let us know your thoughts in the comments!