I've went from a i7-4770K & GTX 760 + 8GB ram -> i7-6700K & GTX 980ti + 16GB ram, and there is a notable difference. However, only notable. That kind of change in a normal circumstance should otherwise be substantial. My game runs effectively at the same exact performance @4K resolution on my new PC as it did in 1080p on the old one. Since more pixels is simply more graphical information, there's no CPU tax. However, start increasing render distance, and the CPU has to take in all of the physics data that accompanies it. Including wind, weather, and ANYTHING happening in those far out scenes. Even stressing my machine, I could get up to about 7km object and terrain distance at 900p with a 20-25fps range. CPU gets hit hard. Partially due to the fact that arma 3 is a 32bit application and can't use hardware like it should.