Marketing description

Add 4 external USB 3.0 ports to a low profile or standard computer, through PCI Express. The PEXUSB3S4V PCI Express USB 3.0 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 USB 3.0 controller 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 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.
UASP is supported in Windows 8 and Server 2012. In testing UASP performed with up to a 70% faster read / 40% faster write speed over traditional USB 3.0 at peak performance.
At the same peak in testing, UASP also showed up to an 80% reduction in required processor resources.
Test results were obtained using an Intel Ivy Bridge system, StarTech.com add-on USB 3.0 cards, a UASP-enabled StarTech.com enclosure, and a SATA III solid state drive.