The Adaptec RAID 5405 is equipped with industry-leading dual core RAID on Chip (ROC), the latest x 8 PCI-Express connectivity, & 256MB of DDR2 cache to deliver over 250, 000 IO per second & 1.2GB/s. Four internal ports in this Unified Serial controller allow you to connect up to 256 SATA/SAS disk drives through SAS expanders. The Adaptec RAID 5405 features Adaptec RAID Code (ARC) with RAID levels 0, 1, 1E, 5, 5EE, 6, 10, 50, 60, JBOD, as well as Copyback Hot Spare.