The HP Smart Array P440ar Single Port PCI-Express 3 x8 12Gbps SAS Mezzanine Storage Controller Card is a high-performance storage controller designed for HP servers. It offers a single port connection with a PCI-Express 3 x8 interface, allowing for fast data transfer rates of up to 12Gbps. The card also includes a 2GB Flash Back Write Cache, which provides a temporary cache for write operations. This cache helps to improve overall system performance and protect against data loss in the event of a power failure. The HP Smart Array P440ar Storage Controller Card is a reliable and efficient solution for managing storage in HP servers.