gistfile1.rb

module MA; end
module MB; end
module MC; end
module MD; end
module ME; end

class A; end

class B < A
  include MA
  include MB
  include MC
  include MD
  include ME
end

class C < B; end
class D < C; end

require 'benchmark'

class A
  100_000.times do |i|
    define_method "a#{i}" do
      1
    end
  end
end

@d = D.new
@a = A.new

methods = []
100_000.times{ |i| methods << "a#{i}".to_sym  }

GC.disable
Benchmark.bm do |x|
  x.report("flat") { 100_000.times{ |i| @a.send methods[i]  }  }
  x.report("deep") { 100_000.times{ |i| @d.send methods[i]  }  }
end

gistfile2.txt

chruby 2.0.0 && ruby dispatch.rb && chruby 2.1.0 && ruby dispatch.rb

gistfile3.txt

       user     system      total        real
flat  0.030000   0.000000   0.030000 (  0.031963)
deep  0.040000   0.000000   0.040000 (  0.036419)
       user     system      total        real
flat  0.040000   0.000000   0.040000 (  0.035921)
deep  0.040000   0.000000   0.040000 (  0.041264)