Get http requests benchmark: sync vs. celluloid vs. em

Gemfile

source :rubygems

gem 'celluloid'
gem 'em-synchrony'
gem 'em-http-request'

results.txt

       user     system      total        real
em:   2.440000   0.510000   2.950000 (  4.980928)
celluloid:   3.610000   0.910000   4.520000 (  6.500888)

test.rb

require 'rubygems'
require 'bundler/setup'
require 'benchmark'

N = 2_000
POOL_SIZE = 50
URLS = ["http://ya.ru"] * N

require 'net/http'

class NetHttpTest
  def get(url)
    Net::HTTP.get_response(URI(url)).message
  end

  def self.test
    URLS.map {|url| new.get(url) }
  end
end

require 'celluloid'

class CelluloidTest
  include Celluloid
  Celluloid.logger = nil

  def get(url)
    Net::HTTP.get_response(URI(url)).message
  end

  def self.test
    pool = self.pool(size: POOL_SIZE)

    futures = URLS.map {|url| pool.future.get(url) }
    futures.map(&:value)
  end
end

require 'em-synchrony'
require 'em-synchrony/em-http'
require 'em-synchrony/fiber_iterator'

class EmHttpRequest
  def get(url)
    EventMachine::HttpRequest.new(url).get.response_header.status
  end

  def self.test
    results = []

    EM.synchrony do
      EM::Synchrony::FiberIterator.new(URLS, POOL_SIZE).each do |url|
        results.push new.get(url)
      end

      EventMachine.stop
    end

    results
  end
end

Benchmark.bm do |x|
  # x.report('sync: ') { NetHttpTest.test }
  x.report('em: ') { EmHttpRequest.test }
  x.report('celluloid: ') { CelluloidTest.test }
end

Is Celluloid that much slower than event-machine for http requests?