In version 1 does not use 2048x2048 textures. Now I will write another answer. Wait.
1. Search for yourself in your mods folder and other folder file hash 5D18E55E5DF1D418, use the default search windows.
2. Try a clean(no SaS modactivator) version 4 10 1 with these files:
Try to use these EXE and Wrapper files: https://www.mediafire.com/file/8gl27iac7fsgql0/EXE%20and%20Wrapper.rar
3. Let me know the results of experiments.
I did search for 5D18E55E5DF1D418 file in my game, and did not find it, except the one which is in "Carsmaster Light in the IL2 (beta) v.2 (4 10 1)".
I made new install of 4.10.1 version. Put exe and wrapper in it and try to run the game, but the game load just till 95%, until that it just stand with the loading screen at 95%.
Also I tried it (stock 4.10.1 version) with the new "il2_core.dll" that you provided later. It also just stand at 95% loading.
Then I tried new "il2_core.dll" with the "Carsmaster Light in the IL2 (beta) v.2 (4 10 1)" in my moded game (V 4.10.1 with SAS ModActivator 2.72) and it is working now. Console shows exactly this:
Created a 2048x2048 RenderTexture with BPP(8, 8, 8, 8 )
Depth = 24, stencil = 8
PBuffer: suitable formats: 6
Created a 2048x2048 RenderTexture with BPP(8, 8, 8, 8 )
Depth = 24, stencil = 8
So, it is working
I don't see so many difference in visual aspect, but than again that could be because I was already using nvidia inspector and some other nvidia graphic enhancements tools.
But I see dramatic increase in FPS count, maybe even for a 30-40%! Now it is going in hundreds
Game goes very smoothly and I don't have any stuttering, not even low above water. Also I don't have any artifacts, everything looks normal.
I forgot to mention, my processor is: AMD Athlon 64 X2 Dual, 5000+, 2,60Ghz.