Unless I can find a 1394b to SAT bridge, more SATA drives will be of no use. Only five directly connected hard drives are allowed in the system due to RAM limitations. The four primary drives are the 15K.3 (boot/apps only, no data), 300GB PATA, 300GB SATA, and 400GB PATA. The fifth drive is coonected through the swappable bay - there are about 15 removable PATA drives. There are three internal backup drives for data zPATA on firewirees - 300, 300, and 400GB, naturally. They are only turned on a few times per day during the backups. In addition there is one external firewire enclosure with 2x200GB drives (hardly used anymore), one with 6 x 250GB drives, and one with a removable bay so that drives can be insetred withou robioioting. It is madness, sheer maedness...