Apple File System (APFS) is Apple’s proprietary file system: the software structure an operating system uses to organize and manage files on a storage device. It is designed with encryption in mind and optimized for flash and SSD storage. APFS is not a physical disk, a backup service, or a separate storage product. Apple uses it across Mac, iPhone, iPad, Apple TV, Apple Vision Pro, and Apple Watch. Apple’s security guide describes its role and design.
What does APFS do?
A file system records where data belongs and how files and directories relate to one another, so an operating system and its apps can find and update them. APFS provides that foundation on Apple devices. Apple lists encryption, copy-on-write metadata, shared container space, file and directory cloning, snapshots, fast directory sizing, and atomic safe-save primitives among its features.
As an Amazon Associate I earn from qualifying purchases.
Copy-on-write means APFS writes changed data or metadata to new locations rather than overwriting the existing version in place. Apple describes its I/O-coalescing, copy-on-write design as a way to pursue performance while maintaining reliability; that is a description of the design, not a published benchmark or guarantee of a particular speed.
Quick wins for a faster PC:
Clear out junk files and repair common Windows errorsFree Scan →Scan for outdated or missing drivers - takes under a minuteDriver Scan →Repair Windows errors before they cause bigger problemsFix Now →How do APFS containers and volumes relate?
An APFS container is a shared storage pool. It can contain multiple APFS volumes, which draw from the container’s available space as needed. In Apple’s description, the container’s available space is its capacity minus space used by all of its volumes. Disk Utility can also set a volume reserve (space held for that volume) or quota (a limit on its use). Apple’s Disk Utility guide explains these settings.
#1 Best Overall
- MADE FOR THE MAKERS: Create; Explore; Store; The T7 Portable SSD delivers fast speeds and durable features to back up any endeavor; Build your video editing empire, file your photographs or back up your blogs all in an instant
- SHARE IDEAS IN A FLASH: Don’t waste a second waiting and spend more time doing; The T7 is embedded with PCIe NVMe technology that brings fast read and write speeds up to 1,050/1,000 MB/s¹, making it almost twice as fast as the T5
- ALWAYS MAKE THE SAVE: Compact design with massive capacity; With capacities up to 4TB, save exactly what you need to your drive – from large working files to game data and everything in between
- ADAPTS TO EVERY NEED: Whether using a PC or mobile phone, count on the T7 for extensive compatibility²; It’s a true team player when it comes to heavy-duty application usage or file-saving
- HI RESOLUTION VIDEO RECORDING: Record Ultra High Resolution (4K 60fs) videos directly onto the T7 Portable SSD with your favorite camera or mobile devices; Supports iPhone 15 Pro Res 4K at 60fps video and more³
This differs from treating every volume as a fixed, separate partition: volumes in a container share free space, although reserves and quotas can constrain how it is used. The exact layout depends on how the storage is configured and what device or operating system it serves.
Mac startup volumes depend on macOS version
For a Mac startup container running macOS 10.15 or later, Apple documents at least five volumes: Preboot, VM, Recovery, System, and Data. System holds startup files and native macOS apps; Data holds changeable user and installed content. This is Apple’s documented startup layout, not a rule that every APFS container has five volumes.
Rank #2
- Get NVMe solid state performance with up to 1050MB/s read and 1000MB/s write speeds in a portable, high-capacity drive(1) (Based on internal testing; performance may be lower depending on host device & other factors. 1MB=1,000,000 bytes.)
- Up to 3-meter drop protection and IP65 water and dust resistance mean this tough drive can take a beating(3) (Previously rated for 2-meter drop protection and IP55 rating. Now qualified for the higher, stated specs.)
- Use the handy carabiner loop to secure it to your belt loop or backpack for extra peace of mind.
- Help keep private content private with the included password protection featuring 256‐bit AES hardware encryption.(3)
- Easily manage files and automatically free up space with the SanDisk Memory Zone app.(5). Non-Operating Temperature -20°C to 85°C
On macOS 11 or later, the system volume is captured in a snapshot, and the Mac boots from that snapshot. Apple’s signed system volume documentation explains that macOS cryptographically verifies system content and can use APFS snapshots to restore the prior system version if an update cannot be completed.
Free tools Windows power users keep installed
One-click scans. No signup required.
What are APFS snapshots, and are they backups?
A snapshot is a point-in-time representation of a volume’s state. Snapshots support macOS system startup and recovery operations, including the version-restoration behavior Apple documents for system updates. A system snapshot should not be treated as a complete, independent backup of personal files: it has a specific system role and does not by itself establish that a separate, recoverable copy of all your data exists.
Rank #3
- MADE FOR THE MAKERS: Create; Explore; Store; The T7 Portable SSD delivers fast speeds and durable features to back up any endeavor; Build your video editing empire, file your photographs or back up your blogs all in an instant
- SHARE IDEAS IN A FLASH: Don’t waste a second waiting and spend more time doing; The T7 is embedded with PCIe NVMe technology that brings fast read and write speeds up to 1,050/1,000 MB/s¹, making it almost twice as fast as the T5
- ALWAYS MAKE THE SAVE: Compact design with massive capacity; With capacities up to 4TB, save exactly what you need to your drive – from large working files to game data and everything in between
- ADAPTS TO EVERY NEED: Whether using a PC or mobile phone, count on the T7 for extensive compatibility²; It’s a true team player when it comes to heavy-duty application usage or file-saving
- HI RESOLUTION VIDEO RECORDING: Record Ultra High Resolution (4K 60fs) videos directly onto the T7 Portable SSD with your favorite camera or mobile devices; Supports iPhone 15 Pro Res 4K at 60fps video and more³
Which APFS format options are available?
For Macs using macOS 10.13 or later, Disk Utility lists four APFS formats. They combine two independent choices: whether the volume is encrypted and whether filenames are case-sensitive.
| Disk Utility format | Encryption | Case-sensitive names |
|---|---|---|
| APFS | No | No |
| APFS (Encrypted) | Yes | No |
| APFS (Case-sensitive) | No | Yes |
| APFS (Case-sensitive, Encrypted) | Yes | Yes |
Case-sensitive formats treat names such as “Homework” and “HOMEWORK” as different. For a typical Mac volume where that distinction is unnecessary, the standard APFS format avoids introducing case-sensitive filename behavior. Choose an encrypted or case-sensitive variant when the relevant requirement calls for it; Apple’s format guide lists the options.
Rank #4
- Note: Magsafe is not available in this version
- High-speed Data Transfer: Lexar external SSD ES3 supports USB 3.2 Gen 2 up to 1050MB/s read and 1000MB/s write to transfer files fast for more efficient work. (Performance may be lower if not supporting USB 3.2 Gen 2 on Mac and other systems)
- Wide Compatibility: Lexar Portable SSD ES3 compatibility with iPhone 17 series (Not supported on iPhone 14 and older models), Android mobile devices, laptops, cameras, Xbox X|S, PS4, PS5, gaming console, and more
- On The Go: Lexar external solid state drive ES3's thin, stylish, and durable design, weighs 42g and is only 10.5mm thick, making it smaller than a card and easily fits in your pocket. It comes with a Type-C cable for plug-and-play convenience
- Data Safety First: Lexar SSD ES3 includes Lexar DataShieldTM 256-bit AES encryption software to protect files
Where is APFS supported?
Apple identifies APFS as the default Mac file system for macOS 10.13 or later and supports it for bootable and data volumes. Although it is optimized for flash and SSD storage, Apple says it can also be used with older systems that have traditional hard drives and with external direct-attached storage.
What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
That Apple-platform support does not mean every operating system can read APFS natively. Apple’s Disk Utility guide identifies MS-DOS (FAT) and ExFAT as Windows-compatible format choices. If a drive needs to move between operating systems, check the devices and OS versions involved before choosing a format.
How does APFS encryption differ from FileVault and system integrity?
APFS is designed with encryption in mind, but that phrase should not be read as meaning every APFS volume is automatically protected in the same way. Apple’s Data Protection overview describes platform-specific key protections for flash-stored data on Apple devices with an Apple SoC, including APFS keys that can be subdivided per extent. The details vary by device and chip generation.
For Apple silicon Macs, Apple says Data Protection uses a volume key by default, while users must still opt in to FileVault for the full protection that ties the encryption key hierarchy to their password. FileVault’s role is distinct from APFS’s file-system role. Likewise, signed system volume verification is a separate system-integrity mechanism: Apple distinguishes its cryptographic verification from APFS metadata checksums. These mechanisms do not amount to a promise that APFS alone prevents every attack or data-loss event.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
