result

$ ruby 01.rb
       user     system      total        real
   0.880000   0.000000   0.880000 (  0.884170)
   0.880000   0.000000   0.880000 (  0.888569)

test.rb

class A
  def a; end
end


class B
  def a1; end
  def a2; end
  def a3; end
  def a4; end
  def a5; end
  def a6; end
  def a7; end
  def a8; end
  def a9; end
  def a10; end
  def a11; end
  def a12; end
  def a13; end
  def a14; end
  def a15; end
  def a16; end
  def a17; end
  def a18; end
  def a19; end
  def a20; end
  def a21; end
  def a22; end
  def a23; end
  def a24; end
  def a25; end
  def a26; end
  def a27; end
  def a28; end
  def a29; end
  def a30; end
  def a31; end
  def a32; end
  def a33; end
  def a34; end
  def a35; end
  def a36; end
  def a37; end
  def a38; end
  def a39; end
  def a40; end
  def a41; end
  def a42; end
  def a43; end
  def a44; end
  def a45; end
  def a46; end
  def a47; end
  def a48; end
  def a49; end
  def a50; end
  def a51; end
  def a52; end
  def a53; end
  def a54; end
  def a55; end
  def a56; end
  def a57; end
  def a58; end
  def a59; end
  def a60; end
  def a61; end
  def a62; end
  def a63; end
  def a64; end
  def a65; end
  def a66; end
  def a67; end
  def a68; end
  def a69; end
  def a70; end
  def a71; end
  def a72; end
  def a73; end
  def a74; end
  def a75; end
  def a76; end
  def a77; end
  def a78; end
  def a79; end
  def a80; end
  def a81; end
  def a82; end
  def a83; end
  def a84; end
  def a85; end
  def a86; end
  def a87; end
  def a88; end
  def a89; end
  def a90; end
  def a91; end
  def a92; end
  def a93; end
  def a94; end
  def a95; end
  def a96; end
  def a97; end
  def a98; end
  def a99; end
  def a100; end
end



require 'benchmark'

n = 10000000

Benchmark.bm do |benchmark|
  benchmark.report do
    n.times { A.new }
  end

  benchmark.report do
    n.times { B.new }
  end
end