each_benchmark.rb

#!/usr/bin/env ruby -w
require "benchmark"
require 'benchmark/ips'

ARRAY = (1..1_000).to_a

Benchmark.ips do |b|
  b.report "each" do
    ARRAY.each do |element|
    end
  end

  b.report "for ... in" do
    for x in ARRAY
    end
  end
end

__END__

drax :: ~/scratch> ruby each_benchmark.rb   
Calculating -------------------------------------
                each      1269 i/100ms
          for ... in      1143 i/100ms
-------------------------------------------------
                each    14075.7 (±13.4%) i/s -      69795 in   5.064338s
          for ... in    12982.5 (±12.0%) i/s -      64008 in   5.016542s