I recently got a 4K monitor. I remembered that the least optimized games ever is Arma and DayZ, I decided to see how long it would take my computer to melt while running DayZ in 4K, but I was getting a solid 60 FPS which I never got while running in 1080p. Sure, there was the occasional lag spike, but I never dropped below 45 FPS. I have all the graphics settings up as far as possible, like I had in 1080p. But in 1080p, I run at about 30-45 FPS. Can anyone explain this?