(ArmA 2)
I have that, and I wanted to like it. I just could not get into it. That and it tired to kill my pc, for some reason I just can't get the game to a constant playable state.
Yes, it's one big resource hog. If it's any worry, after you have it running, it'll do its best to kill your character in dozens of innovative and unfair ways ... it's just
that kind of a game. Or rather, military simulation.

My favourite rage-inducing memory is when, after running for over an hour (real time) through the landscape and not meeting even a single enemy, I got one-shotted by a sniper I didn't even get to see. And had to restart the mission.