PORTABLE SOLID-STATE DRIVES

Fast external storage for better backups, and more

Group test

Reviewed by HOWARD OAKLEY ON TEST...

• CalDigit Tuff nano Plus
• Crucial X8
• OWC Envoy Pro SX
• Samsung T7 Shield
• SanDisk Extreme
• Seagate One Touch

An external solid-state drive (SSD) isn't just faster than a hard disk, it also works better with the Apple File System (APFS).

Storing your Time Machine backups and large Photos or Music libraries on an SSD ensures access stays fast, instead of grinding to a halt as happens on a hard disk. Going solid-state also changes the drive's life expectancy: few hard disks last five years, and many die earlier. Invest in an SSD and it should last as long as 10 years.

Picking the right SSD isn't a matter of getting the fastest you can afford. There's a balance to be struck between speed, capacity and cost. SSD performance is primarily limited by the interface: in reality, USB 3.1 Gen 2 (10Gbps) delivers no more than 1GB/sec, and Thunderbolt 3 or 4 (40Gbps) in practice won't exceed 3GB/sec. That's still much faster than a HDD at a dismal O.1GB/sec, though.

Here's our pick of the crop of SSDs, compared not just using cost per terabyte, but also taking their performance into account, as speed in MB/sec per £ per TB.

How we tested

Each SSD tested was connected using the cable supplied to a Thunderbolt 4 port on a Mac Studio (Max), and formatted in APFS. Read and write speeds were measured using Stibium, with 10 repeats for total transfers of over 50GB, and Amorphous DiskMark.

The single APFS volume was reformatted and Ventura 13.0 installed. The Mac Studio was restarted from the external SSD and time recorded from the startup chime to the appearance of the login window.

Things to consider…