Prevent the Game Bar From Appearing in Full-Screen Games To ensure Windows isn’t recording gameplay in the background, open the Game DVR settings screen and ensure the “Record game in the background” option is unchecked. This option is disabled by default, but it can slow things down if you’ve enabled it. This leaves fewer resources for actually rendering and playing the game.
Even if you have a beefy graphics card, though, this will require a constant percentage of your graphics horsepower while playing a game.