Screen flickering in 3d applications when power cord is plugged!

Everytime i start a 3d application, the screen starts to flicker and it's utterly unplayable. If i happen to unplug the laptop, it works fine.

I tried different power management settings and it doesn't change anything. If the laptop is plugged = flicker / If it's unpplugged = fine.

I have an inspiron 15 with amd a10-8700 (radeon r6).