(#2778/4778/9778) PCI RAID Disk Unit Controller (i5,270, 8XX, 5101, 5065, 5074, 5075, 9074, 9075)This controller with a 104MB write-cache, provides RAID-5 protection and compression for internal disk units, and also supports internal tape and CD-ROM units. #2778/4778 supports both compression and non-compression modes. The #2778 controls Ultra2, Ultra, and Fast Wide SCSI disk units. In addition to RAID-5 protection for disks, #2778 serves as a high-performance controller for disks protected by system mirroring or disks with no protection.The #2778 controller supports a maximum of 15 disk units. A minimum of four disk units of the same capacity are needed for a valid RAID 5 configuration.. For best performance use disks, disk controllers, and storage expansion devices capable of Ultra2 SCSI performance.

 2778/4778/9778 are all the same feature