The ARC-1211X Serial ATA ll RAID host adapters are high-performance PCI-Express bus to SATA ll Disk Array host adapter. The controller can provide up to 4 SATA ll peripheral devices on a single host adapter. When properly configured, the SATA host adapter can provide non-stop service with a high degree of fault tolerance through the use of RAID technology and advanced array management features. The 4 port Serial ATA RAID Host adapter is low-profile PCI cards-ideal for 1U or 2U rack-mount system. It is used the same RAID kernel of its field-proven external RAID controller.