Overall summary of a year’s testing external hard disks and SSDs ranging in cost from $50 to more than $200 per TB. Which is best?
SSD
Two reasons for paying more and using SSDs are that they’re faster and more reliable. Data on failure and reliability don’t appear as clear as the ads, though.
With the right enclosure, a Samsung 980 PRO NVMe SSD delivers transfer speeds of around 2.8 GB/s. Does that make booting from it any faster, compared with an SSD at half the speed?
It depends whether you’re going to boot macOS from it, on the space required for snapshots, and how large they could become. And there’s more.
Which is faster with a hard disk: using APFS or sticking with HFS+? Are there any differences in their performance on SSDs?
What’s our purpose? What factors confound the results of tests, and how to eliminate them? Which tests? What should we believe, and where do we go from here?
There’s evidence to suggest that original M1 Macs write more slowly to external SSDs in some configurations. Does this extend to later models with M1 Pro or Max chips?
Thunderbolt 5 isn’t available yet, and in any case will probably offer no more than 6 GB/s. So what is the way ahead for Apple in its successors to its M1 series chips?
Which of the external disks tested can be used to boot from? Do they work reliably with Secure Boot? Could you boot from an external hard disk?
Armed with just a couple of flashy Thunderbolt NVMe SSDs and his home-made benchmarking app, we discover whether Thunderbolt is any better than USB 3.x.
The Eclectic Light Company 