Performance of game depends on computer's power option?

When I go to Control Panel > Power Options, if my computer's power option is set to high-performance (which is what I usually have it set at) I get framerate drops from 60 fps down to around 20 fps, but when my computer's power option is set to balanced, the framerate drops don't occur. I'm not sure what setting it to balanced optimizes in my scene (GPU maybe), but I would like to know to get rid of the framerate drops on high-performance/other modes. Thank you :)