Steam Link performance compared to Nvidia Gamestream

[superfrancesco]

Hello,
I'm using both Steam Link and Nvidia Gamestream to stream games from my main pc (i5 3570k, GTX 970, 16gb ram, ssd) to a Nvidia Shield 2019 (with 1gbps network).
Both work fine, but performance is noticeably better with gamestream. Steam Link is still ok, but i get micro stuttering that is not visible while playing via gamestream.
Is there some hidden setting or something to make steam link better?
I already tried all possible combinations of settings with steam link: i tried using HW or SW encoding on the host, I enabled/disabled network traffic priority, i tried the fast/balanced/beatufil settings on the client, tried both h264/h265 decoding on the client.
With each tests performance seems the same: fps in game are always solid at 60fps, but the microstutter is not going away.
Maybe gamestream uses a different hw encoder? Is there any way to make steam link relay on gamestream encoding?