I'm wondering is MKW GPU intensive? I can usually do 4x IR in other games I play but not MKW. I usually get around 80% on 4x. I even notice a few small stutters at the beginning of a race on 1x. I do not use AA. I'm using the latest developer version of Dolphin. I am positive Dolphin is not resorting to my cpu's integrated graphics.
[color=green]Windows 7 x64 / i5 4690k @ 3.5 GHz / GTX 970 / 8GB RAM[/color]