not sure what memory you have in your pc but the rest of your machine is similar to mine, but you have a better cpu.
I have a i7 4790
Win 10 Enterprise 64bit
Aourous GTX 1080ti 11GB
SSD for OS
2TB 7200 WD Black for games and data
now things to know.
nvidia drivers.. DO NOT use the latest drivers.. they cause micro stutters! use 384.94-desktop-win10-64bit-international-whql (assuming you have win10 64bit they are older drivers from July last year but are the best ones for Pimax.. no micro stutters and super smooth!!
next i am using piplay 3.0, although the ghosting is slightly worse in this version than the latest 2.x driver.. its up to you, but as i like to test the drivers i always go for the latest.. for me the speed is no different.
Put Piplay on 3.0 (trust me) and as you have a 1080ti, also set the resolution to the highest in piplay.. dont bother with 1080. these are my settings
Now into SteamVR settings. As piplay have their own rendered.. you need to turn off ALL of the steamvr performance settings
Launch SteamVR and click drop down then settings. Then click on Performance. make sure ONLY Allow asynchronous reprojection is enabled
Next goto Developer tab and set it like this
Supersampling to the lowest setting 0.6
Enable Always on Reprojection
Check for Steam - ticked
Now in game settings..
Personally i was using VR Ultra, as you can tell from my post above, but i have found that just using ULTRA graphics settings is actually better.. i get better FPS, no lag, no shadow artifacts, and the planets dark side light up a bit when i approach which really helps.
another thing to do if the game is too dark for you is to switch to pimax video mode and modify the nvidia control panel on the pimax screen to better represent the colours/brightness you want.
From what you describe.. i suspect that the Nvidia driver is the main cause of your performance problems.. it is the same performance issues i was having before i reverted to the older driver.. after that.. i have ZERO stutters or performance issues in any area of the game including high graphics areas like stations, planets, suns, rings etc.
good luck and maybe i will see you in game you will find me in game 'CMDR Enopho'