Reducing video settings will make the game run faster at the expense of graphical quality. The video options you choose in-game have a large effect on your FPS. Note: Please test any new changes in a custom game (with bots or by yourself) first.
To access these options press ESC in-game and select INTERFACE. You can access them in-game by pressing ESC and selecting VIDEO. As a starting point, try setting each option to its lowest value. Playing around with these settings will help you find a sweet spot between performance and quality. Lowering these settings will make the game run faster at the expense of visual quality.