benchmark.rb

require 'benchmark'

class Foo1
  def foo
    "bar"
  end
end

class Foo2
  module Other
    def foo
      "bar"
    end
  end

  include Other

  def foo
    super
  end
end

class Foo3
  def foo
    "bar"
  end

  alias old_foo foo
  undef_method :foo

  def foo
    old_foo
  end
end

n = 10_000_000

foo1 = Foo1.new
foo2 = Foo2.new
foo3 = Foo3.new

Benchmark.bm(20) do |r|
  r.report('normal') do
    n.times { foo1.foo }
  end

  r.report('with super') do
    n.times { foo2.foo }
  end

  r.report('with delegation') do
    n.times { foo3.foo }
  end
end

jruby.txt

                          user     system      total        real
normal                1.939000   0.000000   1.939000 (  1.939000)
with super            2.309000   0.000000   2.309000 (  2.309000)
with delegation       1.439000   0.000000   1.439000 (  1.439000)

mri-1.9.3.txt

                           user     system      total        real
normal                 3.250000   0.000000   3.250000 (  3.278874)
with super             4.420000   0.000000   4.420000 (  4.454511)
with delegation        3.970000   0.000000   3.970000 (  4.001511)

rbx.txt

                          user     system      total        real
normal                1.704741   0.000000   1.704741 (  2.116214)
with super            5.235204   0.001000   5.236204 (  5.369124)
with delegation       1.488773   0.000000   1.488773 (  1.508955)