This SCSI storage expansion option is attached directly to the blade server and is supported only on the IBM BladeCenter HS20 with 800MHz front-side bus supporting Intel Extended Memory 64 Technology. This option supports two IBM Ultra320 hot-swap SCSI hard disk drives (HDDs). It includes an Ultra320 SCSI controller with integrated RAID-1E mirroring capacity. Maximum HDD storage capacity is 293.6Gb.