Been running some performance monitoring on my PC the last few days (approx 10 hours of gameplay in total) and discovered that DCS has surprisingly little effect on CPU, memory and disk loads.
My CPU (older version 2,8 ghz quadcore I7) was never above 30%, my memory was constant on 4gb usage (even though i have 16gb available) and the disk load spiked once or twice every minute or so, not affecting game performance at all.
Moving on to my graphics card, an "old" Asus 580GTX, the game used every bit of resource it could get its hands on, constantly utilizing between 90% to 100% load, depending on buildings within range, units on the ground and firepower being delivered on the battlefield.
To me (though im no expert) the results indicate that CPU, memory and disk is no problem at all aslong as you dont buy 5+ year old hardware. Graphics cards however is the alfa and omega when it comes to high FPS in DCS. Not that this is much of a suprise, but im really surprised at just how little CPU, memory and disk load effects game performance.
So if your buying a new computer because DCS was performing poorly on your old system, id guess you'll want to add a new gfx card with your new configuration.
My 2 cents of research.