I notice you are over the 2 hour Steam refund limit so I'm going to assume you can't refund this.

If you are running on Windows 10 and have not yet told this game to run in Windows 7 compatability mode this may be one of the factors preventing stable gameplay, also to note if your windows 10 is x86 and not x64 this may also prevent your entire computer from utilizing all of it's available resources. (Yes, MS still made 32bit Windows 10 <_<)

I have known people who updated from an x64 Windows 7 to a x86 Windows 10 and lost much of their PC's performance.

I for one can play this game in 4k, downsampled or not, maxed settings with mods, and matain 60FPS with no trouble, I am however on Windows 7 x64 professional....judging from your specs you should be capable of the same! something is not working as it should, you really need to figure out what's wrong with your pc.

Dude you have some bad shit then. I have FX-9590, 290X Lightning x2, 16GB DDR 3 1866 MHz and i run this game perfectly fine 1080p with statble frames

Alt tabing then returning to the game will 7 times out 10 make you lose 40 FPS with this game it's not recommanded you do that. And there are time and place's through out the game where the frames will flicker from 60/25 to 60. Also when booting up sometime you'll get bad static sound just close it and reopen till it stops. Or you could just go play it on the PS3 no problem.

It's a pretty poorly done PC port from a game made in 2012. With a 1070 if your not alt tabing and you can't hold more then 40+ frames at a time it's you driver not the game.