bench_object_id.rb

require 'benchmark'

(ARGV[0] || 1).to_i.times do
  Benchmark.bm(40) do |bm|
    bm.report("1M calls to obj.object_id") do
      o = Object.new
      1_000_000.times { o.object_id }
    end
    bm.report("1M calls to Object.new.object_id") do
      1_000_000.times { Object.new.object_id }
    end
  end
end