Is Collision Detection a big factor (CPU cycles being burnt) in the low FPS?
Another popular sim has a situation where the player can look at some areas of a town and have their 60fps, but to look at another area, the fps plummets. Noted that some of the buildings are solids.

Did you create an SLI profile? By default there isn't one.....this game don't use physx either

Yes I did and if physx are not used by the game why does it invluence the results?! Same for the sli when one change the sli manager(s) from the game to the graphic card driver(s).
When I say I put my settings at very high it is all my settings (one click change).
This is a track file, I hope it works, of this short test mission in a Spitfire MKIa oct.
https://hotfile.com/dl/165184329/d9b..._test.trk.html

I have made a step backward and reinstalled the steam original version of the game the one without the 1.07 patch and no crashes anymore, not one! I have tried most of the test I did with the 1.07 patch and no crash of the game at all. So I must conclude it is not my PC but the patch how is faulty! Sorry. :!: Now I am reinstalling the 1.07 patch because the Spitfire MKIa oct and all 100 octane RAF planes are more fun to fly.

Don't know why so many are having crashes to DT, I have never had this happening. Is it just an online thing or are some that are just off line players like myself having CTD? I tried to get the CTD that some are talking about but just can't make it happen.

I'm running the latest patch and the latest Nvidia beta drivers (304.79)

Enable the SLI and physx indicators in the Nvidia control panel and they will be displayed on the left side of your screen when either is used in a game.
If it don't display it's not in use.

.
I have tested the same mission again in two settings;
Medium with grass and shadows vsync and ssao fps min 3
Very high vsync and ssao on everything very high or original fps min 6
Also I set clouds at medium. Same route as first test see first post to see track that still work.
No more crashes.