Apple Partition Map

See how CleanMyMac speeds up your device with your own eyes at zero cost by taking advantage of the company's 7-day free trial. After the testing period, you can still use the Mac optimizer risk free due to the 30-day money guarantee. Get free access to CleanMyMac for 7 days without limitations. It includes the full package to optimize your computer. This is a standard for the layout of the partition table on a storage disk using globally unique identifiers (GUIDs). As part of the Unified Extensible Firmware Interface (UEFI) standard, GUID is a bootable standard for systems with EFI firmware such as macOS. Non-Intel Macs won’t support this bootable standard, hence the only option available to them is the Apple Partition Map (APM). Used on disks formatted for use with 68k and PowerPC Macs, the Apple Partition Map is the scheme that defines how the data is organized. Starting with OS X Tiger, both APM and GUID partitions can be used for accessing volumes, but PowerPC-based Macs can only boot from APM disks . While Intel-based Macs generally boot from a GUID Partition Table, they are all able to start the operating system from APM and Master Boot Record (MBR) using the BIOS-Emulation called EFI-CSM. Now you know which partitioning map is which, the next time you insert an external drive or want to partition the built-in storage disk of the Mac, it will be easier to choose between the available options. Mac OS Extended (Journaled) Mac OS Extended (Journaled, Encrypted) Mac OS Extended (Case-sensitive, Journaled) Mac OS Extended (Case-sensitive, Journaled, Encrypted) MS-DOS (FAT) ExFAT APFS (macOS High Sierra’s new file system ) APFS (Encrypted) APFS (Case-sensitive) APFS (Case-sensitive, Encrypted). If you don’t see the partition map scheme option, it is likely because Disk Utility doesn’t list all volumes. This will prohibit Disk Utility from erasing the disk and show you an error message. To address this issue, you should click on the View button located in the top-left side of the Disk Utility dialog box and select “Show All Volumes”. From that point on, Disk Utility will ask for your partition map preference, and the formatting process will be smoother . Share your thoughts, ask questions, and connect with other users. Your feedback helps our community make better decisions.