The new generation of Adaptec Unified Serial controllers meets your need for maximum performance, scalability, and flexibility for enterprise-class applications, including network attached storage (NAS), online transaction processing (OTLP), web, digital surveillance, and streaming applications. The Adaptec RAID 51645 is equipped with industry-leading dual core RAID on Chip (ROC), the latest x8 PCI-Express connectivity, and 512 MB of DDR2 cache to deliver over 250,000 IO per second and 1.2 GB/s. With sixteen internal ports and four external ports, this is a high port count controller with the flexibility to connect up to 256 SATA/SAS disk drives through SAS expanders in a configuration tailored to your business needs. The Adaptec RAID 51645 features Adaptec RAID Code (ARC) with RAID levels 0, 1, 1E, 5, 5EE, 6, 10, 50, 60, JBOD, as well as copyback hot spare. Adaptec Storage Manager provides one-view centralized management of all your Adaptec RAID controllers. The Adaptec RAID 51645 also integrates the latest PCIe connectivity, the broadest operating system support, including open source Linux drivers, a battery backup option, and proven compatibility.