Western Digital doesn't want you to run out of backup storage, at least for a long time. And most people won't with the company's new massive capacity 20TB My Book Duo storage system.
Not to be confused with a true network-attached storage (NAS) device, the My Book Duo is a compact box designed to plug directly into your PC. It does not have an Ethernet port or any networking features, so if you need that functionality, you will have to look elsewhere.
For simple backups, however, the My Book Duo is a serviceable solution. It comes with RAID-optimized WD Red hard drives (I've been running a WD Red HDD in my main PC for several years now) with specialized firmware, running in RAID 0 out of the box. WD claims it can hit sequential read speeds of up to 360MB/s. If you're not comfortable with trusting your backups to a RAID 0 array, you can reconfigure the drives to RAID-1 for redundancy or use JBOD.
The My Book Duo also features auto management of drive operations to help ensure read/write cycle data integrity, and 256-bit AES hardware encryption with WD Security.
If you have a USB Type-C port on your PC, the WD My Book Duo will connect to it with an included USB-C cable and port. It also has two additional USB Type-A hub ports for connecting other accessories, such as drones, action cameras, keyboards, mice, USB drives, and to sync and charge your smartphone.
The 20TB capacity will set you back a cool $800. If that's too rich for your blood, there are less expensive (and capacious) models, including 16TB for $600, 12TB for $420, 8TB for $330, 6TB for $290, and 4TB for $260. All of these are available now direct from WD and backed by a three-year warranty.