Review: ioSafe Duo
Erik Vlietinck
Issue: March/April 2020

Review: ioSafe Duo


Manufacturer: ioSafe

Product: Duo

Price: $399-$899 based on configuration


The ioSafe Duo is a hard drive/SSD unit for two disks that can be set up in RAID 0, 1, JBOD or SPAN configurations. As with all ioSafe digital storage equipment, the unit is fireproof, waterproof and theft-proof. It’s available as an empty box or pre-loaded with two hard disk drives of 4TB or 8TB each. The unit supports drives of up to 12TB, has a USB-A port and one USB-C port at the front, and connects to a computer through a USB-C type USB 3.2 Gen 2 port. In theory, the unit can deliver 10 Gbps throughput.

Inside my 8TB test unit were two Seagate IronWolf disks. Those are Seagate’s NAS disks. NAS disks are specifically tuned for many start-stop cycles and continuous use. The IronWolfs that are in my 8TB ioSafe Duo are 5,900rpm drives. Not the fastest of the pack, but the most silent.

The unit is made of pitch black matte metal with a laser-etched flame on one side and the ioSafe logo on the front door. It weighs a back-breaking 15kgs (33lbs). Those 15kgs come from the fireproof and waterproof materials that are responsible for the size of the beast — it’s about 1.5 times the size of a CalDigit T4. Behind the heavy, fireproof front door is a waterproof door. A nice side-effect of this massive physical protection is that this RAID box is absolutely silent. You can’t hear the disks spinning nor the fan running. There’s simply too much mass for the noise to reverberate into audible levels.

The Duo is designed to resist a temperature of up to 840 degrees Celsius (1,544 Fahrenheit) for 30 minutes and ingress from waterjet and submersion in three meters of water for 72 hours. That’s three days, yet everything, even the RAID jumpers and fan in the back is exposed like on ordinary equipment, without further protection. That’s due to DataCast and HydroSafe technology, both of which ioSafe successfully patented in May 2007.

The Duo is built for longevity in other areas as well. Its fan, for example, can be replaced with the use of a screwdriver, without you even having to open the box. Furthermore, if you want to replace disks — or simply start with an empty Duo — that’s possible too. Inside the shipping box you’ll even find a specially-designed hex tool that flexes to prevent you from under/over-tightening the screws or damaging the waterproof gasket. However, regularly “rotating” the disks inside is not advised, as the waterproof materials do wear if you often disassemble them.

The one point that’s probably going to fail before anything else is the set of disks inside. That’s why ioSafe advises to keep them set at the default RAID 1 configuration, which offers disk failure protection. Of course, if you want the most stringent protection in that department, you’ll need a RAID 5 box (and even then you’re not 100 percent protected as even the briefest of power glitches while the RAID is rebuilding will render the checksum, on which RAID 5 depends to rebuild the data after disk failure, useless).

The Duo is your best bet for a safe local backup and much, much more secure than cloud backups where you have to take into account a number of issues, like exposure to hacking. It’s relatively fast as well, although the Duo isn’t a speed demon. The fastest throughput I was able to squeeze out of the 5,900rpm disks was 220MB/sec. If you fill it up with two SSDs, you should be able to reach speeds of around 400MB/sec, even in RAID 1 configuration.

The Duo can be had for $399 if you buy the empty box. For my 8TB test unit you’ll pay $649. A 16TB version retails at $899. The Duo comes with two years of free data recovery service included.