Roku devices with an Ethernet jack are Fast Ethernet. This is 100 Mbps, with real world speeds around 92 Mbps. The WiFi radios/chips they use are not particularly high speed either. The highest WiFi speed I've recorded on any of my Roku devices is my Ultra 4800, which I've seen reach about 210 Mbps. You were never seeing 200 Mbps on a wired connection. If that was the reported number, it was inaccurate.
But you need to remember what Roku has designed these devices for: streaming from an Internet source. At the present time, there's no online provider that streams at more than 25 Mbps, so there's no demand for higher speeds. Yes, those of us that stream from local media servers would like higher speeds for our UHD rips. But I've also tested my 4800 using the USB port, so no network bottleneck. Even the most powerful processor in the 4800 can't process video bitrates above about 160 Mbps. Even that speed I saw some video stuttering, so not a smooth playback. For this use, a Roku simply isn't the best device. But for any currently available online source, their network connections are more than adequate.
One last comment about the network speeds reported by the Roku device. Virtually all of my devices older than the 4800 have never reported the speeds I measured on the 4800. I don't know if the networks were that much slower on them, or if they were finally reported more accurately in the newest Roku devices. But regardless of the reported connection speed, I still never had any issues with online streaming sources. Only with my local media, and even then only with UHD movie rips.
Dan
Roku Community Streaming Expert
Help others find this answer and click "Accept as Solution."
If you appreciate my answer, maybe give me a Kudo.
I am not a Roku employee, just another user.
