If graphics tasks slow down your Mac
If your portable Mac is slower than expected when you perform graphics-intensive tasks, such as playing games or editing video, open Energy Saver preferences. Depending on your Mac, you may see options that let you improve graphics performance in exchange for shorter battery life.
On your Mac, choose Apple menu > System Preferences, then click Energy Saver.
Do one of the following:
If you see Graphics options, select Higher Performance.
You need to log out and then log in again for the change to take effect.
If you see the “Automatic graphics switching” option, deselect it.
Your Mac will always use high-performance graphics.