OWC Mercury Elite Pro Dual mini
Data protection; FireWire, eSATA
No Thunderbolt; only USB 2.0
US$199.99 (320GB + 320GB) + shipping
With two hard drives under the bonnet, the OWC Elite Pro Dual mini is more about security than speed.
The OWC is the odd one out here in that it takes two physical drives. You can run them as one big ‘striped’ drive (RAID0), which boosts speed and capacity but risks losing all your data if even one drive fails. Alternatively you can mirror them (RAID1), which sacrifices storage capacity but keeps your data safe if one drive fails.
Designed for old-school Macs, the OWC lacks Thunderbolt and USB 3.0. Instead you’ve got USB 2.0, eSATA, FireWire 400 and FireWire 800, so on a modern MacBook you’re stuck with USB 2.0. PC users, on the other hand, will appreciate the speed of eSATA.
Copying data to and from the OWC via USB in RAID1 (mirrored) is only marginally faster than the other USB drives – we saw up to a 5 percent speed improvement.
Switching to RAID0 (striped) saw a 40 percent speed boost when copying from the OWC, but this this is still less than half the speed of Thunderbolt. You’d see a performance boost if you used Solid State Drives, but it wouldn’t compensate for the lack of Thunderbolt.
Macworld Australia’s buying advice.
At first glance the OWC seems pretty disappointing alongside the Thunderbolt drives, especially the Seagate which has the option of USB 3.0 and FireWire 800.
But to be fair the OWC is a niche product that’s not for everyone. You’d only bother with it if you intended to run it in mirrored RAID1 for the extra data protection. Even then the need for separate power limits how you can use it. It might suit those who want to move data between offices and are more concerned with data protection than raw speed.