Two (2) external 5Gbps SuperSpeed USB 3.0 ports with up to 2.133Gbps maximum transfer rate(*1) * Compliant with PCI Specification 3.0 * SuperSpeed USB 3.0 is backwards compatible with USB 1.0/1.1/2.0 devices * Built-in with 4-pin Molex power connector for added power source to better support power hungry bus-powered devices * Supports Windows XP/Server 2003/Vista/Server 2008/Windows 7