Multiple devices demand more bandwidth.The same holds true for other streaming services as well as for game-streaming services like Twitch. However, you’ll want even faster speeds if you plan to connect several devices at once. Netflix says you need 5 Mbps to stream full HD content and a data rate of 25 Mbps (megabits per second) for 4K Ultra HD content.What internet speed do I need? Quick tips To see if you really need to pay a lot more for faster connectivity, Tom’s Guide asked broadband experts and staffers at several of the top ISPs and this what we found.