What is the best format for external hard drive Mac photographers?

As a photographer shooting with a Mac, having an external hard drive to store and backup your photos is essential. However, there are a few different formats you can use to format your external hard drive. Choosing the right one can impact performance, compatibility, and ease of use. In this article, we’ll compare the top options – APFS, exFAT, and HFS+ – to help you determine the best format for your external hard drive as a Mac photographer.

What is an External Hard Drive?

An external hard drive is a storage device that can be connected to a computer externally, rather than inside the computer’s casing. It allows you to expand your storage capacity beyond the internal hard drive in your Mac.

External hard drives connect to Macs either wirelessly or via USB, Thunderbolt, or FireWire cables. They are powered either via the computer connection or an external power source.

Once connected, the external hard drive acts as extra storage space as if it were an internal drive. You can store, access, and backup files just like you would on your internal hard drive.

For photographers, having one or multiple external hard drives is essential for photo storage and backups. As photo and video files grow larger in size with increasing megapixels and resolution, external hard drives provide expanding storage capacity in a simple plug-and-play way.

Why Format is Important

While Macs can generally read from some formats like exFAT without any extra work, the best performance and compatibility depends on formatting your drive correctly.

Formatting prepares the hard drive by organizing the way data is stored on it and clearing any previously saved data.

Choosing the right format can impact:

  • Read/write speeds – some formats are faster than others
  • Compatibility – older Macs may not support newer formats
  • Maximum file size – file size limits vary between formats
  • Encryption and security features available
  • Reliability and error checking capability

The right format also needs to support the file system your Mac uses. All modern Macs use Apple File System (APFS), while older Macs used HFS+.

With the importance of formatting in mind, let’s compare the main options for external hard drives: APFS vs. exFAT vs. HFS+.

APFS (Apple File System)

APFS (Apple File System) is the default file system for all internal hard drives on modern Macs running macOS 10.13 High Sierra and later. It was designed specifically for use with solid state drives (SSDs) and flash memory storage.

The advantages of APFS for external hard drives include:

Optimized for SSDs and Flash Storage

APFS is optimized for the way data is stored on modern SSDs and flash storage. This allows for faster read/write speeds versus traditional hard disks.

Strong Encryption

APFS offers built-in strong encryption using AES-xts. This allows files to be encrypted in a secure manner without noticeable performance loss.

Space Efficiency

With APFS, available space is optimized effectively through copy-on-write metadata, compression, and space sharing. More of your drive capacity can be used to store files versus overhead data.


Checksum and write timing metadata helps keep data secure and errors minimal. The integrity of files on APFS is strongly protected.

Crash Protection

metadata in APFS is both persistent and consistent. This provides crash protection in the event of power interruption. Files will remain intact through crashes or forced restarts.

Time Machine Support

APFS volumes can be used as destinations for Time Machine backups, allowing for versioned backups on an external drive.


– Only readable on macOS 10.13+
– Maximum file size of 16 EiB
– Not reversible – difficult to revert back to HFS+


exFAT (Extended File Allocation Table) was introduced in 2006 as an optimized FAT32 file system without the limitations of FAT32. It is widely used for external storage devices to work across platforms.

The advantages of exFAT for external hard drives include:

Cross-Platform Compatibility

exFAT can be read and written to by both Macs and Windows PCs. This makes it a good option for external drives that will be used across operating systems.

No File Size Limit

exFAT does not have a file size limit like FAT32. This allows it to work well with large media files.

Faster than HFS+

exFAT allows for faster read/write times on many external hard drives compared to HFS+.

Simple Format

As an optimized version of FAT32, exFAT uses a lightweight format that enables compatibility and performance.


– No built-in encryption
– Less overhead for error checking versus APFS
– No Time Machine support
– Maximum volume size of 128 PiB


HFS+ (Hierarchical File System Plus) is an older Mac file system used before APFS. It is optimized for mechanical hard drives rather than SSDs.

The advantages of HFS+ for external hard drives include:

Time Machine Support

HFS+ volumes can be used as destinations for Time Machine backups on older versions of MacOS, before APFS Time Machine support.


HFS+ uses journaling to improve reliability. This tracks file system changes to improve crash recovery.

Suits Mechanical Hard Drives

HFS+ is designed around the way traditional mechanical hard disk drives store data. This works well for non-SSD external drives.


– Slower than APFS
– Older format with less optimization for modern drives
– Case sensitivity can cause compatibility issues
– Maximum volume size of 8 EiB
– No built-in encryption

Verdict: APFS is Best for Modern Macs

Based on the advantages and limitations of each format, **APFS is generally the best choice for most external hard drives used with modern Macs**.

The optimized performance, strong encryption, and Time Machine support in APFS makes it ideal for Mac external storage. It is reliable, fast, and optimized for the way modern computers work.

Here are some cases where exFAT or HFS+ could still be preferable:

  • Cross-platform shared drives – Use exFAT if the drive will be accessed by both Mac and Windows systems.
  • Older Macs – HFS+ may be required for Time Machine support on Macs predating APFS.
  • Large media files – exFAT has no file size limit, unlike APFS.

For most Mac-only external hard drive uses, especially for photographers storing large photo libraries, APFS is recommended. Simply format the drive using Disk Utility on a modern Mac running High Sierra or later.

How to Format APFS

Formatting to APFS is straightforward using Apple’s Disk Utility application. Follow these steps:

  1. Connect the external hard drive to your Mac.
  2. Open Disk Utility (in Applications > Utilities).
  3. Select the external hard drive from the sidebar.
  4. Click Erase at the top.
  5. For Format, select APFS.
  6. Give the drive a name and click Erase. This will format to APFS.

Once complete, the external hard drive will be formatted to APFS and ready to use. Any previous data on the drive will be deleted and overwritten.

Optimizing APFS External Drives

There are a few steps you can take to optimize external hard drives formatted with APFS:

Use Native Mac APFS Encryption

Turning on encryption through Disk Utility when first formatting to APFS will encrypt the drive using Apple’s native encryption. This is seamless, fast, and secure without third party software required.

Enable TRIM

TRIM in APFS allows the operating system to inform the SSD which blocks of data are no longer in use and can be wiped and reused. This maintains the performance of SSDs over time.

Using TRIM requires OS 10.13+ and compatible hardware. Enable it by executing:

sudo trimforce enable

Partition for Time Machine

When formatting to APFS, optionally partition the drive so part of the capacity can be used exclusively for Time Machine backups.

APFS vs Other File Systems Summary

File System Optimized For Max File Size Time Machine Encryption
APFS SSDs and Flash 16 EiB Yes Yes
exFAT Large media files No limit No No
HFS+ Mechanical drives 8 EiB Yes No


The best format for external hard drives used with Macs is generally APFS. It has speed, compatibility, encryption, and optimization advantages that make it ideal for modern macOS versions.

There are cases where exFAT or HFS+ may still be useful, like for cross-platform drives or older Mac OS versions. But for most Mac external storage uses, especially for photographers, APFS is now the go-to choice.

By understanding the differences between APFS, exFAT, and HFS+, you can choose the right format for your external hard drive’s needs and get the best performance on your Mac.