Some benchmark about pure CPU computation:
https://benchmarksgame-team.pages.debian.net/benchmarksgame/...
Erlang is really slower than Java
Go and Java now:
https://benchmarksgame-team.pages.debian.net/benchmarksgame/...
You see the big difference, Go and Java are on part but Go usually takes way less memory than Java.
You can't have everything, message passing / immutability with no performance hit.