Purchased the 40ft Cat 8 ethernet cord for use with day trading- the flat Cat 8 cord only delivered about a third of the speed of my previous round Cat 6 cord.Various speeds in Mbps from macbook from same distance to the router (with Gigabit service):Flat Cat 8 cord: 399.38 download, 305.05 UploadWifi: 290.60 download, 260.40 uploadCat 6 (Round): 933.32 download, 895.95 uploadAs you can see, significant difference between the round Cat 6, and the flat Cat 8. Found some info on flat cords being lSee full review