1. Supports up to four Serial ATA 3G devices total 2 external Serial ATA (eSATA) 3Gb/s Ports 2 internal Serial ATA 3Gb/s Ports2. eSATA connectors provide hot-plug capabilities and better performance than USB or 1394 solutions 3. Supports up to 2TB of storage per controller (500GB HDD x 4-ports) 4. Supports Native Command Queuing (NCQ) 5. Supports Tagged Command Queuing (TCQ) 6. Large LBA support for drives above 137GB 7. 66MHz PCI host bus interface for up to 266MB/s bandwidth8. Supports Serial ATAPI devices9. Onboard Disk Activity LED Headers10. Dual controller support within a system 11. Simple solution for users who require internal or external 3Gb/s SATA storage space and ideal for desktops and workstations using SATA drives