The docks we tested offered a range of port speeds, from USB 2.0 at 480 Mbps to USB. To measure the read and write speeds of each, we ran AJA System Test speed tests using Samsung’s Portable SSD T5 for the USB ports and the now-discontinued LaCie Bolt 3 for the Thunderbolt ports. USB-C ports are less common, as are extra Thunderbolt ports.