The HPE Smart Array P420 Controller is a low profile, 6 Gb/s, PCIe 3.0, Serial Attached SCSI (SAS) RAID controller that provides enterprise class, second generation storage performance & data protection for select HPE Pro Liant Gen 8 rack servers & tower servers. It features eight internal SAS ports & delivers increased server uptime by providing advanced storage functionality, including online RAID level migration (between any RAID levels) with flash back write cache, global online spare, & pre-failure warning. Data compatibility between HPE Smart Array Controllers means customers can easily upgrade to future Smart Array Controllers. HPE 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 (Advanced Data Mirroring). Increased performance & data protection, with reduced initial setup time. Up to 3x performance improvement over past generation, using up to 2 GB DDR3-1333 cache memory. Long term data retention with flash back write cache (FBWC) offered as a standard feature, up to 2 GB capacity. Support for RAID 0/1, 1+0, 5, 50, 6, 60. New predictive spare activation for enhanced rebuild & maximized uptime. Reduction in parity initialization from 45 days to 5 hours.