Are you using radeon pro still?
I removed mine as it had started to cause a load of graphical coruptions in the menu and I have seen no performance drop I'm still getting 60 fps but yes I do get the random spikes you mention!

Im not happy to performance at all, sometimes my game is smooth and steady 60fps, sometimes not, little rubberband effect with ground when not steady 60fps, what is weird, same place, same time and so on?. I really hope next patch makes something big to this engine, rof is smooth even on supersampling on and AA 2x and it looks gourgeous.

Hey Kankkis, I saw you selected option 3 from the performance poll, odd as I thought we had similar setups, perhaps we could compare settings etc.