Step 4: Go into your Windows Control Panel and go to Power Options and set it to High Performance.
Step 3: Download and Run Then Disable Cortana and Other Windows Features you do not need. Step 2: Download and Run to unpark your cpu cores.
So with a few simple steps you may be able to improve your FPS in Arma 3, i have done this for a few people during my Arma time and for most it has made an increase of FPS and Smoothness in Arma, There are probably 100 more things you can do that i wont list in this guide.