CPU usage highly depends on the number of connected clients, not that much on message throughput. You can experiment with the excellent rabbitmq-perf-test tool to get some ballpark numbers.
I have a system that only pushes 5k messages per second but it needs 32 cores.
Yeah that sounds about right. Of course if you had 200 connections and 50 queues you'd more likely be seeing 100000 msg/s. The number of connections and queues has a big effect on total throughput.
I have a system that only pushes 5k messages per second but it needs 32 cores.