About Fusion Drive, a storage option for some Mac computers

Fusion Drive combines the performance of Flash storage with the capacity of a hard drive.

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Presented as a single volume on your Mac, Fusion Drive automatically and dynamically moves frequently used files to Flash storage for quicker access, while infrequently used items move to the high-capacity hard disk. As a result, you enjoy shorter startup times and—as the system learns how you work—faster application launches and quicker file access.

Fusion Drive manages all of this automatically in the background. And it comes already set up, so you don't have to do anything to make it happen.


Fusion Drive became available as an option for iMac and Mac mini models introduced in late 2012. Fusion Drive now comes standard on some iMac and Mac mini models, and is a configurable option on others. For even faster performance, you can configure a model that uses only flash storage (SSD).

Learn more

  • You can use Disk Utility to add a single macOS partition to the hard disk on Fusion Drive, and that partition will function as a separate volume, not as part of Fusion Drive. Disk Utility then dims the  button to prevent additional partitions. If creating a Windows partition, use Boot Camp Assistant instead.
  • You can use Target Disk Mode to mount Fusion Drive from another Mac that is using OS X Mountain Lion v10.8.2 or later. 
  • Learn what to do if your Fusion Drive appears as two drives instead of one in the Finder.
  • An external drive can't be used as part of a Fusion Drive volume.

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