The pexusb3s25 2 port pci express usb 30 card lets you add two usb 30 ports to your pci express enabled computer system with an optional lp4 power connector to connect to your system power supply and deliver up to 900ma of power per port to usb 30 bus powered devices 500ma for usb 20 enhanced with uasp support usb attached scsi protocol this usb 30 controller performs up to 70 faster than conventional usb 30 when paired with a uasp supported enclosure note uasp is not s