Controller Interface Type:Serial Attached SCSI Width:2.25 Inch Depth:7.5 Inch Height:9.5 Inch It features four internal and four external SAS ports and delivers increased server uptime by providing advanced storage functionality, including online RAID level migration with flash back write cache, global online spare, and pre-failure warning. Data compatibility between HP Smart Array Controllers means customers can easily upgrade to future Smart Array Controllers. HP Smart Array Advanced Pack 2.0 firmware makes it easier for customers to protect their data with advanced functionality for this next generation of Smart Array controllers, including features such as RAID 1 ADM