Currently, the only enterprise Hitachi drives shipping are the 2TB and 3TB Hitachi drives. They show a 1.5 TB on their website (http://www.hitachigst.com), but it's not shipping yet. With the correct host adaptor card, you will get 1500 - 1600 MB/sec in a 16 bay with 2 TB or 3TB drives. Yes, they are fantastic. And yes, the 3TB Hitachi drives work directly in a Mac Pro chassis. Only 2 Hitachi 3TB drives striped RAID 0 will give you 300MB/sec. Hard to believe.