My friend stumbled upon this recently, we were both having stuttering on high settings and i had to use laptop high instead of desktop high which i found odd as i have a fairly highpowered custom rig.

Go to options, Display options (this is the default to pop up) and scroll down to the bottem. There is an FPS lock hidden there, select none and apply. This will unbound your client from 60 FPS

Me and my friend now have max selected with no FPS problems at all. Hope this helps some of you!!