The RocketRAID 2640x4 SAS RAID Series offers the flexibility to support either 15,000 rpm SAS hard drives for performance or lower cost SATA hard drives for capacity. The ability to deploy either type of drives allows the computer system to be optimized for specificapplication and cost requirements. Disk with SAS interfaces are designed to meet the performance and reliability characteristics required for RAID systems. SAS drives retain all of the reliability and performance advantages of traditional SCSI and while eliminating the weaknesses of the parallel interface.