To activate efficiency mode for a specific program in Windows 11:
Open the Task Manager.
Right-click the program and select "Efficiency mode".
That's it! Efficiency mode is now enabled for the selected program.
Tips:
Only enable efficiency mode for programs that you don't need to be responsive.
If you find that a program is not performing as well as it should with efficiency mode enabled, you can disable it by following the same steps above.
Conclusion:
Efficiency mode is a great way to improve battery life and performance in Windows 11 by reducing the resource usage of specific programs.