Sans Digital TowerRAID TR4UT+B - 4 Bay USB 3.0/eSATA Hardware RAID 5 Tower with 6G PCIe 2.0 HBA (Black) Hardware RAID, supporting RAID 0, 1, 10, 3, 5, JBOD, Clone and hot spare disk. Over 200MB/s read and 170MB/s write performance. eSATA and USB 3.0 interface. Backward compatible with USB 2.0. Bundled SATA 6.0Gbps PCIe 2.0 x1 controller card, support PCIe 2.0 with over 200MB/s performance. Backward compatible with PCIe 1.0 slot is supported. True hardware RAID design within the enclosure, no driver and no additional RAID controller needed.