RAM consumption when splitting mesh

I got a bit messy 3D scan mesh which I need to clean up - mostly cut out unwanted parts. I noticed huge amounts of RAM needed to split meshes.

I ran out of my 32 GB RAM in my attempt to split mesh as shown in the picture.
Is it normal behavior when splitting meshes? Should I send my file somewhere?

That’s not surprising. When you split a mesh, every mesh facet of both meshes are compared with every facet. That’s a boatload of data to keep track of. When the mesh is nasty, it gets worse.

I’d suggest take some time to clean up the messy mesh before you try to split it.

Many times I can’t clean up mesh in any easy way, because it comes with mapped texture.
I am starting be more aware of the limitations and how to fight them.

In this case, there were some disjoint mesh parts that I unjoined before making the split. After that preparation splitting went ok.

It is kinda strange that some parts that are obviously not intersecting with the trimming surface are taken into consideration in a way that they bloat RAM. I wonder how it is done in typical mesh oriented software.

Thanks for your clarification.