[bob1029]

I would add a qualifier of "serializable" to those events or commands. This is the crux of why fintech goes this path. Every order affects subsequent orders and you must deal with everything in the exact sequence received.

The cases you noted are great examples of things that do justify going across the PCIe bus or to another datacenter.

[Retric]

That’s half of it, the other half is each of those events is extremely simple so the amount of computation is viable with a single thread.

If individual threads were dramatically slower the architecture would get unpleasant by necessity. Consider the abomination that is out of order execution on a modern CPU.