Your up-to-20TB backup device, the OWC Mercury Elite Pro Dual

The OWC Mercury Elite Pro Dual features two Thunderbolt 2 ports, one USB 3.1 Gen. 1 port and all of the cables you need to start using it immediately. You can set this small-footprint unit to RAID 0, RAID 1, disk spanning and JBOD modes. It has a black minimal design and you can buy it as a bare enclosure or with disks already installed. I got the chance to test the 2TB version.

First of all, the Mercury Elite Pro Dual is OWC’s simplest Thunderbolt 2 RAID device. It has room for only two disks inside — my test unit came with two 1TB Toshiba drives installed — and no ON/OFF switch. To start the unit, you simply plug in the Thunderbolt or USB 3.1 cable and it starts up.

The Mercury Elite Pro Dual has been rated for a maximum throughput of 474 MB/s. My test unit achieved lower figures in RAID 0, but as I for the time being no longer have a Thunderbolt 3 machine at my disposal, I couldn’t test the unit at its highest performance — I didn’t get higher figures than 300MB/sec, which still is very decent.

The pre-installed Mercury Elite Pro Dual units can have up to 20TB of storage, which is enormous given that there are only two disks to install. The unit has been designed to automatically spin down during periods of inactivity and to power on and off with your Mac, but the single fan at the front of the unit was a little too loud to my liking. I’m sure if you’re in an office with people around, the background noise will swallow the rather high-pitched fan noise the Mercury Elite Pro Dual makes, but in my quiet room, it started working on my nerves after 10 minutes. Even positioning the Mercury Elite Pro Dual on the floor with its sound-deadening carpet didn’t help.

That is easily remedied, however: you just pull the Thunderbolt or USB cable and the unit is automatically powered off completely. OWC does sell the Mercury Elite Pro Dual as an always-on unit for general use, but I wouldn’t mind taking this with me on a video shooting day on location — provided there’s a mains power outlet somewhere nearby. Obviously, the device isn’t as lightweight as you would like it to be (if you want to have a lightweight drive, there’s the OWC Mercury Elite Pro Dual mini or the CalDigit Tuff and both are USB-powered), but it would do brilliantly at immediately backing up your freshly recorded files.

The Mercury Elite Pro Dual is a flexible and external disk drive and a great backup device. I’ve been using it now for a few days via USB 3 as a Carbon Copy Cloner destination and that works brilliantly. The drive only needs to be powered on for half an hour or so and then you can power it down by pulling the cable. I would also recommend this drive as a Time Machine disk drive. Again, you don’t need to keep it running all the time.

Personally, however, I wouldn’t use it as always-on storage for audio or video projects, precisely because of the sound it produces — unless you can position it somewhere you can’t hear it — but then again it may just be my test unit that’s generating this high-pitched noise. The quality of build, the design and disk drives that are installed are all of a high enough quality to use the Mercury Elite Pro Dual as your main data storage for any sort of media task, though. Its price is very decent as well: my test unit costs $397.75.