In this case, it’s generally a good idea to do a clean driver reinstall. This will help remove the old files that can sometimes cause FPS problems.
First, remove the old driver files by using the third party driver remover DDU. You can find a guide on using this program here.
After this, pick up the latest driver from here. Run the installer and select the Nvidia Driver option only. Then I would recommend doing a Custom install and selecting the ‘Perform a clean installation’ option.
Once the driver install has finished, change the Nvidia settings so that the game is using the Nvidia card:
• Right click on the desktop and launch NVIDIA Control Panel --> Manage 3D settings.
• Go to Program Settings tab.
• Select the game to change the graphics processor under “Select a program to customize”. If it’s not is not available, select the specific game from the drop down list.
• Select your “Prefer maximum performance” graphics card under “Power management”.
Then reset the game settings to set everything back to default.