That doesn't make sense though. It was slower loading on the 1080 compared to the 980 which has 8Gb even though it was faster with response and frame rate and had at times spare VRAM which also showed the same slow loading. That was my question, why is would be slower on a much faster PC?
Eg same scene.
980 4GB 50 FPS and loading time of 10-15 sec (LOD 2)
1080 8GB 90FPS , took 30 sec + to load same scene (LOD 1 or LOD2)
That led me to the 2nd question, what actually limits loading if the PC is more than adequate for rendering/computing tasks.?
I'm sure I have worked out the answer to both these now anyway.
I found the issue had something to do with win 10, at least this install as the faster PC also had a win 7 installation on another drive, which then I tried again, SE loaded the same speed as my own slower PC, the issues of non responding keys on the keyboard and menus also went away.
On the 2nd question, I found settings in the main config that allows to adjust terrain/texture loading outside of what is allowed in the graphic setting panel. The time per frame allowed for texture/terrain generation and also another of how many allowed to be generated at the same time I think?
I had found a real time loading required 100ms and 64 tiles on my PC. Default is 50 and 4. I think this really depends on the PC specs on how far you can change these.
I was able to get my system to almost load everything real time but at a large cost of performance of FPS. dropped to about 8-20 fps, but the loading was almost instant ever to far distant terrain. I will be playing around which these again on a faster PC to see what sort of improvements I can get without loosing too much frame rate.
So all good, answered my own questions in the end.
EDIT: I could be wrong but it looks like the 50ms config is the max time window per frame allowed for tiles to load to ensure fps doesn't drop below the 50ms frame time value because I noticed 50ms = 20fps min, 100ms = 10 fps etc... So you can increase it to allow more tiles to load but at cost of min fps. You can increase the tiles loaded to the point to fully unitize the available time window. I found it to be 8-9 on my PC without any loss and much faster loading. So if I got this correct you could set the tiles higher on a faster PC while leaving the max time per frame the same so theoretically achieving faster loading without loss of performance.
Space Engineer will probably need to confirm this but sure seems like that is the way it works.