Does fluctuating FPS hinder performance on Champs like Katarina

Ive been playing kat for some months now. ive gotten the general idea down about her kit and whatnot. Its seems my main issue it is the rate of how rapid her combos need to be at times. I feel like I cant get the most out of her due to my low fps ESPECIALLY in team fighting scenarios. My fps is like 70-65 at spawn and in-lane, during fights and High Activity Scenes drops 45 below. could this be a big factor limiting you from unlocking a champions full potential