The benchmark doesn't "cripple" by de-parallelizing. Execution is already in parallel, it just uses regular collections as the concurrent ones weren't worth the

The benchmark doesn't "cripple" by de-parallelizing. Execution is already in parallel, it just uses regular collections as the concurrent ones weren't worth the performance overhead and in the end Akka ran 44% faster than Erlang. In the comments you refer to having 50% Erlang is roughly the same as 44%, so I don't thing there is much performance difference even though Java/Scala is faster than Erlang in general. Regarding soft realtime requirements Erlang may be a better choice, but I doubt there are too many use cases where it will make much difference.