X-MEDIA 4-Port SuperSpeed USB3.0 PCI Express (PCIe) Controller Card for Desktop PC [XM-UB3204] Super speed usb3.0 transfer rates of up to 5gbps, 10x faster than usb2.0 4 external usb3.0 downstream ports for desktop pcs Usb3.0 specification compliant, backward compatible with usb2.0/1.X Supports pci express rev. 2.0 Support windows xp/vista/7/8.X/10