Why do you think that I'm getting buffering when all other kit using 2.4GHz signal on is reading 30 to 40mb/sec. Does the Roku need faster speed than that to show HD. I didn't know that this model does not receive the 5GHz signal because I get 200mb/sec through that. I'm strongly thinking of sending it back
30 to 40 Mbps is more than enough, but is your Roku getting that? You should be able to see the speed it's getting at Settings->Network->About.
Have you tried other channels (keeping in mind that it only supports channels 1 to 11)? Also, Wi-Fi speed is only half of the issue. If there's something going on between you and the source of the video then there's not much you can do about it. Do all channels/apps buffer or just one or two?
Roku Community Streaming Expert
Help others find this answer and click "Accept as Solution." If you appreciate my answer, maybe give me a Kudo.