Franz Bettag have written up a small post about a benchmark between Akka and Erlang.
Interesting results. On his hardware and specific benchmark Erlang R14B04 did 1 million messages per second while Akka 2.0-SNAPSHOT did 2.1 million per second.
Read more here: http://uberblo.gs/2011/12/scala-akka-and-erlang-actor-benchmarks
…and we still have a lot more performance to squeeze out of Akka.