[tormeh]

Scala/Akka is a lot faster than Erlang, but it also lacks per-actor GC, which means that latency is going to be higher in a Scala/Akka system. Also, the per-actor heaps in Beam means there's no risk of two Erlang actors having a reference to the same memory, whereas that's easy to do in Scala/Akka.

[OvermindDL1]

Actually you'd be surprised at just how fast the BEAM passes messages, especially as it also includes linking, monitoring, cross-process, cross-system, among other features. When creating a multi-thread atomic messaging system in C++ long ago I was able to out-perform the BEAM (though I'd not rank it as significantly out-perform), but once I added failure handling features among others then it never got close to BEAM's speed again in raw message passing.

However, the BEAM is not very fast on executing actual code, it is like Python in that way where it is good to slave out CPU-heavy work; the BEAM is built for async IO, and yes, running a JVM (or C++) system as a node on a BEAM mesh is fantastic for that (or a port, or NIF for small work).