Try disabling the in-game fps limiters you have enabled now. The game seems to be a lot happier when they're not used for the most part.
Keep in mind also that if you have vertical sync enabled, you're only ever going to see frame rates as high as your monitor's refresh rate which is typically 60. Disabling will give higher numbers but likely at the expense of video quality. You may see "video tearing" with it disabled.
Betrifft mich selber, ich werd heute mal versuchen und Bescheid geben ob das hilft