Part of what keeps the high load on the GPU is vsync, as someone mentioned on Answer hub. However, there may be more to it, as u can see here.
Even though that specific post is unity related, and they use locked framerate by default, u can see that vsync actually takes quite some time even when it is working properly.
I don’t know whether the problem in that case is in Unity or Marshmallow… or on the user side of things, but if u lock ur framerate to 60 and test it as a PC preview, u’ll see that the frame still takes around 16ms to show up. For reference, my desktop monitor is also refreshing at 60Hz.
