Western Digital has always played favorites with the Mac with its My Book Studio Edition II line of external hard drives, and the new release of the 4-terabyte model continues the trend.

Apple has positioned the Macintosh line as a premium PC, and the Studio Edition II is also a premium external storage solution: the whopping 4 terabytes of storage capacity (across two drives)  is matched by an equally hefty $649.99 price tag. Users can purchase the drive either through a retailer or through WD's site.

Both the MyBook Studio Edition and Studio Edition II ship with a FireWire 800/400 connection that Apple has endorsed, as well as eSATA and USB 2.0 connector.

The new Studio Edition II is user serviceable, meaning that users can swap new drives in and out. One catch: only WD's GreenPower drives are supported, as the case does not use a fan. RAID 0 functionality is supported for all of the drives; the drives can also be mirrored in a RAID 1 configuration. A capacity gauge is also included so that users can see how much available space has been used.

The My Book Studio Edition II can also be used with Windows PCs, although users will have to suffer through the lengthy format times that Mac users must deal with while using drives that have been preformatted for Windows machines.