Did a regular OC but nothing extreme (other games benefit quite well)
Today i decided to run couple synthetic test, 3dmark and SuperPosition as expected 1080ti runs much better in scores. For example on 1080p high benchmark in SP i get on Vega64 10230 points and of Nvidia I get 16325, same difference in 3dmark as well.
So this is definitely game related issue, most likely driver optimization problem.
Like I said identical MB Asus Ranger VIII and 6700K cpu. (i even OC CPU and memory on PC with 1080ti no improvement)
So basically 1080ti with 240hz monitor will experience a solid amount of tearing
Vega64 Strix - 240-320 fps
Gigabyte 1080 ti Aorus (not extrem version) - 160-240 fps
P.S. No need to point out that drivers for nVidia are set for best performance.