Most games run perfectly at max settings EXCEPT for SMG2

[Man_With_Arrow]

Title- most games run at stable 30/60 FPS on 1080p, internal resolution 4x native, 16x anisotrpoic filtering, anti-aliasing level 8 32 samples... all the enhancements. Even more demanding games such as SSBB run just fine, albeit on slightly tweaked setting (3.5x native, 8x filtering, less AA...) but SMG2 lags at the lowest resolution, no enhancements. I've included screenshots of my settings. What can I do to improve the performance?