I've had four dual-drive RAID enclosures for RAID mirroring. I've never had a single drive in these enclosures to fail, but I've had several controller board failures and have ended up cannibalizing the drives for other purposes. I finally discovered (and should have known for years) that macOS can turn any two same-sized drives into a RAID 1 mirror array (or RAID 0, JBOD, or RAID 10). Two single desktop drives are considerably less expensive than buying a dual-drive unit, and if one goes bad they're cheap and easy to replace and rebuild.
I bought two of these Elements 4TB desktop drives to make into a RAID 1 array. I didn't want the MyBook drives because I didn't want the automatic encryption as a matter of simplicity and reliability. I needed a couple of more USB ports than I had and didn't want to bottleneck my USB 3 hub, so I bought an Anker USB-C to 4 port USB-A 3.0 adapter, since USB-C's bandwidth can absorb in one port anything these 2 drives can produce. Unboxed everything, plugged it in; fired up Disk Utility, formatted each drive for Mac, went to RAID Assistant, chose the drives I wanted, chose RAID 1 and sat back. Time from start to finish: about 15 minutes total, including plug-in time.
So far this setup has worked flawlessly. These drives are cool and almost silent. Transfer rates are good, better than with the dual-drive enclosures. The price was excellent, far less than buying a dual-drive enclosure. We'll see how everything behaves over time.
| Hard Drive | 4 TB Portable |
|---|---|
| Number of USB 3.0 Ports | 1 |
