CPU Speed Menu allows you to switch between the different performance settings of your computer by a single mouse click. It is no longer necessary to open System Preferences, navigating to the Energy Saver pane and selecting the Options item. This is helpful for users who must switch between different speed settings very often, for example when temporarily performing processor-intensive tasks. Switching manually to a speed which meets your current needs best can improve battery load on portable computers, or avoid noise problems with cooling fans and power supply units on desktop computers. This tool does not need any space in the Dock and does not consume processing power while it is running in the background.
You can download the application CPU Speed Menu for free. This allows you to evaluate the software to see if it suits your needs.
The only restrictions are: