Following the introduction of 2TB hard drives earlier this year, Western Digital has expanded its My Book line of external storage solutions with a new model that pairs two such drives together in a RAID 0 stripe for a total 4TB of space. The My Book Studio Edition II comes pre-formatted in HFS+ for Mac computers and is touted as particularly useful for large Time Machine backups, video and photo-editing work.

The two internal hard drives use WD's GreenPower technology for power savings and cool and quiet operation. Connectivity interfaces include eSATA, FireWire 800, FireWire 400 and USB 2.0 and an accessible enclosure lets owners replace one or both drives without having to replace the entire array. The 4TB My Book Studio Edition II is available now for an estimated $650 and Western Digital is backing it with a generous five-year warranty.