Promise E-Class VTrak E610SS SATA/SAS Hard Drive Enclosure is a intelligent, dual controller, SAS/SATA based storage arrays that fundamentally changes storage economics from purchase and set up to operation and upgrades. Four 3Gb SAS (Serial Attached SCSI) x4 host interface ports per controller provide a reliable, high-performance alternative to Ultra SCSI 320 storage applications. Each standard 3U, 19" rack unit supports up to 16 off-the-shelf 3.5" SAS or SATA 3Gb/s drives. Attach up to four SAS JBODs to deliver 80 drive bays of direct attached storage. Direct Attached Storage remains a favorite of SMB operations worldwide. Easy to configure and familiar even to novice system administrators, SAS inherits all of the DAS attributes while leaving its limitations far behind. With advanced multi-pathing capabilities, cascade support and full redundancy, the VTrak E-Class goes where parallel SCSI products cannot reach.