[TheMode]

I feel like CA (single, or multi-state) would work quite well on dedicated hardware, how big could the grid even be? I may be missing the obvious, but it does seem easier to scale compared to cores and manual dispatch.

But otherwise yeah, not the most efficient on current CPUs.

[bob1029]

To be fair, a one-dimensional CA is effectively a sort of UTM with a weird program counter and instruction set. I think the more useful CAs will tend to be of the higher dimensional variety (beyond 2D/3D). Simulating a CA in hyperspace seems problematic even if you are intending to purpose build the hardware.