IIWY, I would aim to be hitting 90FPS 99% of the time on a 1070 or equivalent.
Don't forget the CPU side of things. OH has a minimum spec of an old AMD FX series, they have about half the single thread performance of an I5 from 4 years ago but do have a bunch of threads available. If using DX11 or OpenGL 4.5, make sure to separate the graphics rendering thread and the main game engine thread. Even if you do no additional multi-threading, that will make one hell of a difference on CPU usage. I only bring it up because so many games both new and old fail to do that.