The game runs like ass, even in the vanilla version, if you use the "play game in fullscreen" option in the InitSetting.exe launcher. Never use that option and just use the modded graphics mod to get fullscreen or borderless windowed
Interesting, from what you write it is rather your game should run faster than mine as you have better hardware but you have problems and my is running ok.
I do actually play with "play game in fullscreen" option and my game is running rather well. Maybe the screen resolution is the key, take a look at my settings.
When you say "heavy mods" which do you mean?
It's hard to make a list of the heavy ones.
The thing is that sideloader creator made in his tutorial a statement that mods should have listings in their info subfolder in form of .csv files rather than in .unity3d files because those in .unity3d can't be streamed from mod directly and whole must be loaded into ram instead, that actually should be in your log file.
Most mods actually apply to this advice but some of rather old ones or converted into zipmod from hardcoded files are those more problematic.
Although I don't think that would be your problem as you have 3GB GPU card (comparing with my 1GB), unless you have really small amount of general RAM (I have 16GB).
