same here, i have 16 gb and dcs is using everything but dcs.exe is allocating only 8.3.
Also, is using more than 8gb of vram in 1080p, max usage is around 10 on my system.
Also, very strange, after a few minutes flying around it always unload 2-3gb of system ram and i can see all the ground texture reloading after using the F10 map the first time.