Smoothness is measured by frametime, not frames per second (fps).
You can have 300fps and shit experience.
It's possible for a single frame to take 100ms and the others take 10ms, resulting in 91fps.
But you will feel that frame hit you like a knife on your back...
If you use MSI Afterburner, WITHOUT D912PXY, you can try to put a graph with the frame times.
Also, check your hardware for overheating or underclocking. And make sure you use the right power profile for your hardware.
When I switched to NA to spin. my game is too smoothness in NA. i rly dont understand.
NA mushin tower dummy : 80 90 fps not to much freeze
EU mushin tower dummy : 30 40 fps and to much freeze
I really don't know what I'm doing to my account on the EU