The Allegro 4-Port USB 3.0 PCI Express Card adds four external SuperSpeed USB 3.0 ports to a full-height PCIe 2.0 slot, running its own dedicated controller. It works with USB-IF compliant USB 3.0 and USB 2.0 peripherals, supports hot-plug and hot-swap connection, and is optimised for Thunderbolt for maximum performance when used in a Thunderbolt expansion system. USB Attached SCSI is supported under OS X 10.8.5+ and Windows 8.1+.