system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why is running a game (or anything) in Windowed mode more stressful on a computer than running it in Fullscreen?

I've noticed this myself when playing GTA, I was running the game at half the framerate while running it in windowed (borderless) than when I switched over to fullscreen.
gpt
When you are windowed, Windows not only has to draw your game screen, but all of the other things running in windows too.  Plus, it has to convert the resolution you have chosen to something smaller.

When you run in fullscreen mode, All of the graphics power is reserved for the game alone, and no conversion needs to be done.