Thanks!
Currently 35-40 fps @4K resolution- runs well over 60 at 1440p! Keep in mind that I have really done nothing to optimize the scene- no LODs, no sensible densities for anything 
The performance killer is the directional light and the shadow distance- with those off the scene doubles in performance. With careful LOD creation and use of billboards for distant meshes, a scene like this would easily run really well on most machines. I simply don’t want to spend the large amount of time it takes to properly make good LODs for the meshes for these test scenes!