Portable hard drives have quickly become the go-to solution for bulk external storage. They plug into just about any PC and offer plentiful capacity for media archives, backups, and the like. Seagate's latest serves up 4TB of capacity—and it's the first to do so with mobile drives that can subsist entirely on USB power.
Note that I said drives rather than drive. The Backup Plus Fast 4TB stacks a pair of 2.5" mechanical drives inside a metal enclosure that measures 4.6" x 3.2" x 0.88". These 2TB drives are configured in a RAID 0 array, and Seagate claims that transfer rates peak at 220MB/s.
Unlike 4TB external solutions based on 3.5" hard drives, Seagate's portable RAID box doesn't require auxiliary power. A single USB 3.0 cable is all that's require to connect to the host system. Older machines without SuperSpeed connectivity may not pump out enough power over a single port, so there's a two-pronged USB cable in the box, as well.
Seagate equips the drive with the latest version of its Dashboard software. The app now supports backups for mobile devices, which can sync over local Wi-Fi networks or remotely through cloud-based services like Dropbox. (The portable drive isn't wireless, so it needs to be connected to a host system for mobile backups to work.)
The RAID 0 configuration is less than ideal for backups, but it should at least make file transfers reasonably quick. Seagate is targeting the Backup Plus Fast more at video and photography professionals who need a lot of speedy portable storage. Asking price: $300.