Just a quick list of numbers for those who care RE: mem usage and stuff. Using the DX12 mode
Gear used
3570k @ 4.4
GTX 980 @ 1380 core clock and 3505 mem - EVGA SC ACX 2.0 cooler
2x 4 GB DDR3 @ 2133
Running on a Samsung 840 Pro ssd
ALL game settings set to HIGH - with the exception of - AA turned OFF, AO turned OFF, Memory limit OFF, Vsync ON @ 60
Game set to 1440p
This is for SINGLE PLAYER ONLY - multi player not tested
Prologue - Average 3400 - 3700 Mb memory used - Solid framerates with Vsync - minor stutter with large artillery bombardments on screen
Tank Missions - Average 3000 - 3400 Mb of memory used. Never drops under 60 fps (limited testing with vsync off was 85 - 90 fps)
Air Mission - average 2900 - 3300 Mb - (final air part was around 3750 - due to large amount of stuff happening on screen - cant elaborate without spoilers) - same average frames as previous missions
4K (3840 x 2160) is playable. If you want a solid 60 fps - that can be done but you will need to sacrifice post processing, and bump texture quality down to medium.
I can do more specific 4K testing if people are interested.
970 owners should be able to run @ 1440p without any issues - memory would seem to be around 3500 or less most of the time.