Western Digital 4 and 8 TB My Book Duo

Western Digital (WD) has released two new models of their My Book and My Book Duo external hard drives. The Thunderbolt devices are now available in an 8 TB model which uses a pair of 4 TB drives in an internal RAID 0 configuration. The device has two Thunderbolt I/O connectors that allow you to daisy-chains with other My Book Duo units, or other devices. Now the scary part, the  8 TB variant is priced at $849.99. WD also introduced a 4 TB variant of its My Book USB 3.0 hard drive. The My Book encloses a single 4 TB hard drive priced at US $250.