Koutech 4-Port SuperSpeed USB 3.0 PCI Express (x1) (3x Ext + 1x Int) with 4-pin Molex Power Connector Fully compliant with one-lane (x1) PCI Express 2.0 specification Three (3) external 5Gbps SuperSpeed USB 3.0 ports One (1) internal 5Gbps SuperSpeed USB 3.0 port Up to 5Gpbs maximum transfer rate Supports 32-bit & 64-bit Windows Vista/Server 2008/Windows 7/Windows 8