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    <p>When doing benchmarks, don't use <code>times</code>, because that creates a closure <code>RUN_COUNT</code> times. The extra time taken as a result affects all benchmarks equally in absolute terms, but that makes it harder to notice a relative difference:</p> <pre><code>require "benchmark" RUN_COUNT = 10_000_000 FIRST_STRING = "Woooooha" SECOND_STRING = "Woooooha" def times_eq_question_mark RUN_COUNT.times do |i| FIRST_STRING.eql?(SECOND_STRING) end end def times_double_equal_sign RUN_COUNT.times do |i| FIRST_STRING == SECOND_STRING end end def loop_eq_question_mark i = 0 while i &lt; RUN_COUNT FIRST_STRING.eql?(SECOND_STRING) i += 1 end end def loop_double_equal_sign i = 0 while i &lt; RUN_COUNT FIRST_STRING == SECOND_STRING i += 1 end end 1.upto(10) do |i| method_names = [:times_eq_question_mark, :times_double_equal_sign, :loop_eq_question_mark, :loop_double_equal_sign] method_times = method_names.map {|method_name| Benchmark.measure { send(method_name) } } puts "Run #{i}" method_names.zip(method_times).each do |method_name, method_time| puts [method_name, method_time].join("\t") end puts end </code></pre> <p>gives</p> <pre><code>Run 1 times_eq_question_mark 3.500000 0.000000 3.500000 ( 3.578011) times_double_equal_sign 2.390000 0.000000 2.390000 ( 2.453046) loop_eq_question_mark 3.110000 0.000000 3.110000 ( 3.140525) loop_double_equal_sign 2.109000 0.000000 2.109000 ( 2.124932) Run 2 times_eq_question_mark 3.531000 0.000000 3.531000 ( 3.562386) times_double_equal_sign 2.469000 0.000000 2.469000 ( 2.484295) loop_eq_question_mark 3.063000 0.000000 3.063000 ( 3.109276) loop_double_equal_sign 2.109000 0.000000 2.109000 ( 2.140556) Run 3 times_eq_question_mark 3.547000 0.000000 3.547000 ( 3.593635) times_double_equal_sign 2.437000 0.000000 2.437000 ( 2.453047) loop_eq_question_mark 3.063000 0.000000 3.063000 ( 3.109275) loop_double_equal_sign 2.140000 0.000000 2.140000 ( 2.140557) Run 4 times_eq_question_mark 3.547000 0.000000 3.547000 ( 3.578011) times_double_equal_sign 2.422000 0.000000 2.422000 ( 2.437422) loop_eq_question_mark 3.094000 0.000000 3.094000 ( 3.140524) loop_double_equal_sign 2.140000 0.000000 2.140000 ( 2.140557) Run 5 times_eq_question_mark 3.578000 0.000000 3.578000 ( 3.671758) times_double_equal_sign 2.406000 0.000000 2.406000 ( 2.468671) loop_eq_question_mark 3.110000 0.000000 3.110000 ( 3.156149) loop_double_equal_sign 2.109000 0.000000 2.109000 ( 2.156181) Run 6 times_eq_question_mark 3.562000 0.000000 3.562000 ( 3.562386) times_double_equal_sign 2.407000 0.000000 2.407000 ( 2.468671) loop_eq_question_mark 3.109000 0.000000 3.109000 ( 3.124900) loop_double_equal_sign 2.125000 0.000000 2.125000 ( 2.234303) Run 7 times_eq_question_mark 3.500000 0.000000 3.500000 ( 3.546762) times_double_equal_sign 2.453000 0.000000 2.453000 ( 2.468671) loop_eq_question_mark 3.031000 0.000000 3.031000 ( 3.171773) loop_double_equal_sign 2.157000 0.000000 2.157000 ( 2.156181) Run 8 times_eq_question_mark 3.468000 0.000000 3.468000 ( 3.656133) times_double_equal_sign 2.454000 0.000000 2.454000 ( 2.484296) loop_eq_question_mark 3.093000 0.000000 3.093000 ( 3.249896) loop_double_equal_sign 2.125000 0.000000 2.125000 ( 2.140556) Run 9 times_eq_question_mark 3.563000 0.000000 3.563000 ( 3.593635) times_double_equal_sign 2.453000 0.000000 2.453000 ( 2.453047) loop_eq_question_mark 3.125000 0.000000 3.125000 ( 3.124900) loop_double_equal_sign 2.141000 0.000000 2.141000 ( 2.156181) Run 10 times_eq_question_mark 3.515000 0.000000 3.515000 ( 3.562386) times_double_equal_sign 2.453000 0.000000 2.453000 ( 2.453046) loop_eq_question_mark 3.094000 0.000000 3.094000 ( 3.140525) loop_double_equal_sign 2.109000 0.000000 2.109000 ( 2.156181) </code></pre>
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    1. POWhy is == faster than eql?
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    1. USAndrew Grimm
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    1. COI agree that micro benchmarking is difficult, but using an `each` or a `while`, as long as it's consistent, won't change the relative speed of things. In any case, I've given the answer as to why there is a speed difference.
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      1. USMarc-André Lafortune
 

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