My screen resolution is 2560 x 1600. I cant find the correct settings to solve the problem. I tried setting the max. resolution to 1280 x 720 (in the Unity settings) but it shows no changes.
Holy sh*t. Just saw you activated low resolution aspect ratios. I dont really know what it does but it boost my game to 80 fps in fullscreen and 150fps in the minimized window. Thanks!