gistfile1.txt

λ jruby speed.rb 
      user     system      total        real
define_method :one  0.408000   0.000000   0.408000 (  0.407368)
define_method :two  0.123000   0.000000   0.123000 (  0.122547)
def three  0.078000   0.000000   0.078000 (  0.077790)

∴ /Users/sam/Desktop
λ ruby speed.rb 
      user     system      total        real
define_method :one  0.580000   0.240000   0.820000 (  0.848865)
define_method :two  0.580000   0.250000   0.830000 (  0.842408)
def three  0.350000   0.160000   0.510000 (  0.525318)

gistfile2.rb

#!/usr/bin/env ruby
#
# Methods defined using Ruby's define_method are slower to invoke than normally defined (eval-ed) methods.

require 'benchmark'
 
module Bench
  
 
  class One
    def self.add_slow_method(name,&block)
      define_method(name, &block)
    end
 
    def three
      3
    end
  end
end
 
Bench::One.add_slow_method('one') do
  1
end
 
Bench::One.add_slow_method('two') do
  2
end
 
n = 100_000
Benchmark.bm do |x|
  one = Bench::One.new
  x.report('define_method :one') do
    n.times {one.one}
  end
  x.report('define_method :two') do
    n.times {one.two}
  end
  x.report('def three') do
    n.times {one.three}
  end
end