4 Port PCIe USB 3. 0 Controller Card UASP 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. See our UASP test results below for further details. 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 t