x-52 pro is pretty bad quality tbh :)
sliders and rotaries are pretty much useless because they are so jumpy or something and i dont really see point for that centering technique they used. i guess i got spoiled by the msff2 10 years ago :)
You cant really compare cpu frequencies outside their processor families.
I'd take of and try to fly towards that fps lag monster and pinpoint what is causing it. Does your fps drop if your game is paused too?