"The actual capacity of the IBM is slightly higher, 30738MB vs. 30020MB, due to the layout of the drives. The IBM stores data on both side of 2 disks with a data density of just over 15GB per disk. The Western stores data on 2 sides of one disk and just one side of another, but these
disks have a data density of 20GB per disk. But what does this mean for performance you say?"
FULL STORY @ RIZENET (http://www.rizenet.com/hardware/75gxp_vs_300bb/page1.php)