Hey WillBreaker7, I recommend starting with your GPU and the drivers. In my personal case, I ran into outdated drivers causing FPS issues within D2 at times. You can also check your monitor settings themselves. I know for NVIDIA, you can right click your desktop to bring up the NVIDIA control panel and once there you can select the monitor being used for D2 and confirm the refresh rate and resolution settings are correct. For me personally, I spent a good while turning off and on certain graphical settings inside of D2 to get as smooth of FPS as I could as some elements caused some FPS drops. Let me know if anything helps! FPS issues can be a pain lol.