Irvine-based disk drive maker WD is targeting Mac OS X users with a new external hard drive system, the My Book VelociRaptor Duo, which it says is one of the fastest external HDD systems available on the market. WD said its new system is aimed at Mac computer users and creative professionals, and includes two, 1 TB, 10,000 RPM hard drives. The 2 TB dual-drive system is aimed at editing high resolution video and other high throughput applications like graphic design, digital media, and photo editing. The new system starts at $899.99 and also includes RAID 0 and RAID 1 options; the drive is the second in WD's line that uses Apple's new high speed Thunderbolt interface.