For what I see, there should be no problem running the game with your current system.
Please check the following:
1- On your in-game inventory, you should have a Benchmark item, run it and watch your FPS. Do reply here with the average FPS you saw.
2- Check on your task manager if there's any other program causing the usage issue.
3. Make sure you are running the latest version of the game.
4. If possible, verify if there's any component overheating on your system, as it can limit the amount of processes it can run.
5. Start a new game and check if this persists.
6. Re-install the game and check if problem persists.
If your current safe is lagging but the new one isn't please send me your bugged safe, I will take a look at it personally.
Hoping to solve this for you soon.