Thanks for this track guys
There's one suggestion I have, though.
When you look at tracks by ISI you can see they consist of 600-900 GMT files. The only exception is Spa, which has just below 2000 GMT files, but this track is large, so you may say that "concentration" of GMT files is similar.
In case of Mid Ohio we have over 2000 GMT files and Sebring has over 4000 GMT files.
This is the main reason why these two tracks perform much worse on my system. Cutting track geometry into bunch of small objects will not optimize the track too much for GPU, but will greatly increase CPU demands.
I've made a test once with rF1. I've placed 1000 identical cubes in one GMT file. Rendering time was 0.2ms. Now I've put each cube in separate GMT file - rendering time was 4.2ms.
The reason for it is that GPU is typically capable of rendering a few thousand triangles by the time CPU can prepare next mesh for rendering.
As far as I remember, you had all energy posts in separate GMT files, even though they were concentrated in given areas. Another exampe would be tents in pitlane - despite being identical and standing nearby, they were placed in separate GMT files.
Rendering a mesh requires selecting shader, textures, setting material parameters, binding vertex arrays - all this takes time. While CPU is trying to do all that, GPU is starved.
Collision models are a different story. Game engine should optimize them while loading, but if it doesn't it's better to have collision models chopped into smaller pieces.
But for rendering it's always better to merge objects and limit unnecessary CPU-GPU communication.
Just for a comparison - CryEngine 3 can render entire scene with like 400 "draw calls" - including all lighting, shadows and reflections.
Now imagine that rFactor must render 1000 meshes separately, then again for shadows, then again for reflections.... There's no chance it's performance will be on par with other games in market this way.
I hope this makes sense to you guys

And good timing - I was just looking for a track for some funrace in Nissans
