What speed is this Ethernet adapter capable of? John July 03, 2018 11:51 Updated Follow A. This adapter will support 10/100/1000 (Gigabit) Ethernet speeds. Related articles Quick Guide What if I am experiencing Ethernet issues? What is the difference between the Slim Multi-Port Adapter and the Multi-Port Adapter? What is the Ethernet speed of this adapter? Comments 0 comments Please sign in to leave a comment.