The current SAT SMART Driver extension used to access health data on external drives has limitations in macOS 11 ‘Big Sur’. If your Mac supports macOS 12 ‘Monterey’ or later, we recommend upgrading, as the SAT SMART Driver extension will automatically load during system startup and does not require you to perform the steps listed below.

As a reminder, the macOS supports reading SMART data from internal storage and Thunderbolt connected external storage devices. However, it does not natively support reading SMART data from USB and FireWire external storage devices. To address this, we include the SAT SMART Driver extension, an open source driver that enables support for many USB and FireWire external storage devices, although it doesn’t support all of them. Additionally, some external enclosures may prevent the SAT SMART Driver extension from passing through the bridge chip to read the SMART data from the enclosed storage device. The SAT SMART Driver extension we provide is a universal driver, meaning it works with both Intel and Apple Silicon-based Macs.

Once the SAT SMART Driver has been installed using the existing installation method, perform the following steps.

1. Launch Terminal under macOS Big Sur and issue this command:

sudo /usr/bin/kmutil load -p /Library/Extensions/SATSMARTDriver.kext

2. Type in the administrator password to load the SAT SMART Driver extension.
3. Eject all USB or FireWire drives from the Mac.
4. Physically disconnect all USB or FireWire drives.
5. Wait about five seconds and then re-connect all USB or FireWires hard drives.
6. In Drive Scope, choose Rescan Drives from the Drives menu (Command-Option-R).
7. Any SMART supported USB or FireWire drives should be added to the Device list in Drive Scope.

SMART health data will be available until the next system reboot, after which this procedure will need to be repeated.