HotSpot doesn't matter that much in this test. You end up spending 80% of the time in the kernel and when I tested, the Erlang code only spent a fraction of it'

HotSpot doesn't matter that much in this test. You end up spending 80% of the time in the kernel and when I tested, the Erlang code only spent a fraction of it's time in the emulator loop. In other words, the speed comes from everything but the optimizing compiler. It is from the runtimes.