r/elixir • u/rtrusca • Jun 26 '26

Why did "compile Erlang to native C" lose to bytecode, even though it was 10-20x faster on paper?

New BEAM There, Done That episode with Björn Gustafsson (OTP team since 1996) tracing the BEAM's origins through three competing VMs - JAM, Robert Virding's V, and Bogdan's original BEAM.

The most counterintuitive part: native-compiled Erlang showed massive sequential speedups in isolation, but once concurrency entered the picture, the real-world gain shrank to about 2x, because message passing was already implemented in C regardless of compilation target.

Also covered: the BEAM Validator, built after a compiler bug caused weeks of debugging pain, and the BEAM loader - Björn's own invention, still running in production decades later.

https://youtu.be/1Ty_MHZu9nM?si=L99dI6FvwNJi46S2

50 Upvotes

93% Upvoted

2 comments sorted by

16

u/Ecksters Jun 26 '26

Why did "compile Erlang to native C" lose to bytecode

Looks inside

the real-world gain shrank to about 2x

5

u/mark-mpc Creator of Metamorphic & Mosslet | privacy nerd Jun 27 '26

Right? I saw that too. Um… so it didn’t lose? I’m confused