Been having this issue for a couple of months. My SIM spikes throughout the game and CPU will hover around 80-99% usage even though my temps are good (50-55C on all cores).
GPU hovers around 50% (70C). I get stuttering and slowdowns when the fights are intense and even in close 1v1 situations. I used to set my FPS at 144hz but now it’s at 100 on all low settings. This slightly helped with the usage. Updating/reinstalling my drivers made no difference.
I have an i56600K, GTX 970 and 8 GB RAM.