The 4-port USB 3.0 PCI express card (with SATA Power) adds 4 external USB 3.0 ports to any PCI Express-enabled computer system with support for data rates up to 5 Gbps, while remaining backward compatible with USB 2.0 / 1.x devices. Enhanced with UASP support (USB Attached SCSI Protocol), this SuperSpeed USB 3.0 PCI express card performs up to 70% faster than conventional USB 3.0 when paired with a UASP supported enclosure (Note: UASP requires a compatible operating system). Using a more efficient protocol than the traditional USB BOT (Bulk-Only Transport), UASP technology optimizes transfers by allowing multiple commands to be processed simultaneously, significantly increasing transfer speeds for less wait time on data transfers. The 4-port USB 3.1 PCIe card uses a "stacked" port layout that places the ports one on top of the other, enabling all four USB 3.0 ports to be external facing, while still allowing the card to fit into a small form factor/low profile computer system using the included low profile bracket. Plus, with a built-in SATA power connector, each USB port can provide up to 900mA of power to devices that draw power from a host bus connection (500mA for USB 2.0) by connecting to your computer power supply. This USB 3.0 expansion card is backed by a StarTech..