I have some rigid bodies each with collision shape consisting of many cubes (in compound shape) looking like, say, chunks of Minecraft-like ground.
When these objects start to collide I get heavy performance drops (below 1FPS). This happens even when there are only a few (<10) such objects (though they consists of hundreds of cubes, each).
Is this expected or is it likely I'm making some errors in the world configuration? I understand that my scenario implies lots of contact points (each of the cubes generates a contact point) and it's possibly an issue but on the other hand I have only on order of thousands of cubes altogether, all grouped in compound shapes in just a 10-20 objects.
What would be the recommended configuration of the collision dispatcher/broadphase/solver for such scenario?
I'm using bullet 2.87 (bundled by default with libgdx 1.9.

A test scenario (debug draw enabled temporarily): 9 "pillars" ~100x5x5 falling down, colliding on each other and then ground:
While the shapes below are pretty simple (could be single cubes), I cannot optimize the shapes in my 'real' scenario as they are usually are pretty irregular.
Thanks & regards