Multi-Core Sweet Spot For Ignition?

Is there a sweet spot or ideal configuration for multi-core processing in Ignition?

For example: Does Ignition utilize more that two cores? Is anything greater than four that much better than four alone?

It depends on your workload, but if it’s a bigger system it will definitely use what you give it.

What do you think that threshold might be for a bigger system generally? (Or at what point does multi-threading start kicking in?)

It kicks in immediately, unless your system is literally doing nothing. Ignition is highly multithreaded from the ground up.

You should never have less than 2 cores allocated and seeing as it’s 2019 I’d recommend just never having less than 4.