MacOS High Sierra APFS Fusion Drives Support Confirmed by Apple
Currently, only the Macs that have all flash built-in storage are supported by the new Apple File System.
APFS
Fusion Drives Won’t Support the New Apple File System in macOS High Sierra
The upcoming new Apple File System feature will be limited to Macs with all-flash built-in storage.
iOS 10.3 Will Upgrade Your Device to Apple File System (APFS)
The new APFS is designed to improve support for solid-state storage and encryption technologies.
Apple Reveals New File System That Will Scale From watchOS to macOS, Replace HFS+
Apple introduced the Apple File System (APFS), which has been designed to eventually replace the HFS+ format.