That's what I meant; multiple operating systems threads, not hyperthreaded execution on one core. I don't remember offhand what POV-Ray's support for multi-cor

That's what I meant; multiple operating systems threads, not hyperthreaded execution on one core. I don't remember offhand what POV-Ray's support for multi-core execution is or was. Back in the 90's, there was PVM-POV which ran on a cluster. That's probably what you'd use if you had a dual-socket machine back then. I imagine there was probably an MPI version as well. I assume it supports multicore natively now, since practically all CPUs are multi-core now.