Have you ever tried capping to 31? When using the mod I never had a single stutter or anything, and I have a good eye for it (Why i'm here eh). Maybe you should try that.
31 is smooth no matter what people say, massive fps only matters for example if your playing an online shooter and perfect reaction is needed, where about 130 fps is perfect.
This could also give your gpu a bit of extra resources to get that AO on.
3 GB cards FTW. Then I will have some fun...

