Microsoft's upcoming consoles are going to support a new method for storage expansion, which replicates the speeds of the internal SSD. These external drives are now up for pre-order.
Game drive RSS
Microsoft has teamed up with Seagate to launch the Game Drive, a USB 3.0 hard drive with 2TB of storage, "designed exclusively for Xbox One or Xbox 360" - but you'll have to pay a premium for it.
