CPUSetter adjusts the number of active cores in your Mac CPU(s). It can also enable/disable hyperthreading on supported CPUs.

This requires administrator access to the machine, and a small privileged helper program is installed when you first execute CPUSetter.

A convenient link to the system Activity Monitor is provided so you can observe the impact of changes.
Authentication with your administrator credentials is required to make changes to your system.

The Processes window allows you to change your processes' priority (nice value) and limit the maximum CPU usage of any of your processes. You cannot adjust processes that do not belong to you.

Be aware that you may severely impact the operation of your system by adjusting these parameters.