When i use Maximise on play my framerate drops 100-200 frames per second, is this normal?

When i use a little screen (not miaximise on play) when I test my game, it goes off with a 140-400 frames a second (400 lasts as oten a couple of seconds but I sometimes have 350 up to ten fifteen seconds) but as soon as i go into maxmise it holds very stable on 100-170 frames a second, is this normal?

Well your GPU is rendering 4-5 times the resolution in the full screen mode maybe more based on the size of your Game window. So I think this is expected, especially if your scene’s bottleneck is graphics related.