The HPE Smart Array P841 controller is a full-height, PCIe3 x8, 12Gb/s Serial Attached SCSI (SAS) RAID controller that provides enterprise-class storage performance, increased external scalability, and data protection for select HPE servers. It features sixteen external physical links and delivers increased server uptime by providing advanced storage functionality, including online RAID level migration (between any RAID levels) with flash back write cache (FBWC), global online spare, and pre-failure warning. This controller includes transportable FBWC allowing the data in the cache to be migrated to another controller.