[lukan]

"that make it less than O(n^2), you've introduced tree search or spatial caching that makes your single "core" (WG) per particle diverge"

Well, like I said, I try to use the CPU side to help with all that. So every particle on the GPU checks maybe the 20 particles around it for collision (and other reactions) and not 14000, like it is currently.

That should give a different result.

Once done with this sideproject, I will post my results here. Maybe you are right and it will not work out, but I think a found a working compromise.