I’m running moonlight on a Sony x900h and I get very noticeable input lag trying to run 4k/60. When I turn it down to 1080/120, it significant decreases input lag. I am running Ethernet on both my host pc and client. The tv only supports 100mbit though. Will input lag decrease if I add a usb to Ethernet gbit adapter or is it more of a decoding issue and may need something more powerful like a nvidia shield?
No. Increasing bandwidth does not lower latency.