Most of the Mesa3D demos seem to run.
Comparing Browsers running WebGL was interesting.
Gentoo64 is now good enough to run Firefox and Chromium at the same time.
Benchmarking Browsers does not benchmark OpenGL.
The Mesa demos come with an objviewer
Once the missing alpine skybox images are googled and found you end up with a rotating bunny image floating in mountains.
Celeron core duo 60fps, Gentoo64 25fps.
Swapping the GreatLakesBiplaneHP for the bunny starts to chug the PC - 37fps.
But it does horrible things to Gentoo64, fell over the bleeding edge of current Pi capability
So too many vertices 142305, triangles 283266... is the limit 65K?
https://www.mesa3d.org/systems.htmlllvmpipe - uses LLVM for x86 JIT code generation and is multi-threaded
I think I saw something about LLVM JIT compiling in the WebGL stuff for Chromium, is that one of the tricks used for WebGL speed on x86?