For me, on Windows 10, I found it by
Click "Start" menu button
Select "Settings".
Select "Power & sleep".
On the right hand side, under "Related settings" click: "Additional power settings."
Under "Preferred plans" click on "Change plan settings" for the plan your PC is using.
Click "Change advanced power settings".
You should now see the pop-up in the picture above (in your active language setting). Continuing:
Expand "Processor power management."
Expand "Maximum processor state."
Click on the "100%" link and set it to 99.
Thanks to VanDamage for pointing this out.