Screen brightness toggles and battery LED flashes WHITE when plugged in and running graphics intensive programs

When I run programs that are graphically intensive (games, video editing, design software, etc), my screen toggles its brightness back and forth about every 2 seconds, almost as if it is switching on and off the power profiles of "plugged in" and "battery", which makes sense since the battery indicator LED also flashes. This slows things down a LOT. I know this computer can't run at full speed without being plugged in, which makes me suspect it is an issue with switching back and forth between power profiles for some reason. I've seen many posts on here about how the battery flashing orange, green, or red means something, but mine just flashes white. On and off and on and off...

Any ideas?

Dell Precision M6600 laptop with NVIDIA Quadro 3000M and 8GB RAM