I have a simple scene in which I've scattered 350k pig and rubber toy instances using the point instancer. Everything functions as anticipated and cooks quickly, except for the material variation node. It significantly slows down the process, taking approximately 20-25 minutes to cook. 50k takes seconds, after 60-65k it slow downs exponentially. Task manager shows that Houdini is utilizing only one CPU core, running at 100%. Could this be due to Python usage, as it seems to be single threaded?

Thanks for reporting this.

EDIT: This should be resolved in 19.5.652