Puma offers both multi-threading and multi-process in clustered mode to take advantage of multiple cores. Here's our config/puma.rb that we used with Rails 4.1

Puma offers both multi-threading and multi-process in clustered mode to take advantage of multiple cores. Here's our config/puma.rb that we used with Rails 4.1beta and 2.1.1: https://gist.github.com/9838767 https://gist.github.com/9838767