roar vs ams vs rabl vs jbuilder

bench.rb

require 'bundler'
require 'active_model_serializers'
require 'roar/decorator'
require 'roar/json'
require 'rabl'
require 'jbuilder'
require 'benchmark'
require 'ffaker'

Post = Struct.new(:id, :author, :body, :draft) do
  include ActiveModel::Serializers::JSON
end

posts = []

(1..100_000).each do |id|
  posts << Post.new(id: id, author: FFaker::Name.name, body: FFaker::HipsterIpsum.paragraph, draft: [true, false].sample)
end

class PostSerializer < ActiveModel::Serializer
  attributes :id, :author, :body, :draft
end

module PostsRepresenter
  include Roar::JSON

  property :id
  property :author
  property :body
  property :draft
end

def rabl_template
  '
    collection @posts
    attributes :id, :author, :body, :draft
  '
end

puts '_' * 88

def ams_test(posts)
  ActiveModel::Serializer::CollectionSerializer.new(posts, each_serializer: PostSerializer).to_json
end

def roar_test(posts)
  PostsRepresenter.for_collection.prepare(posts).to_json
end

def rabl_test(posts)
  Rabl.render(posts, rabl_template)
end

def jbuilder_test(posts)
  Jbuilder.encode do |json|
    json.array! posts, :id, :author, :body, :draft   
  end 
end

puts 'with 100_000 records'

Benchmark.bm do |x|
  x.report('AMS') { ams_test(posts) }
  x.report('Roar') { roar_test(posts) }
  x.report('RABL') { rabl_test(posts) }
  x.report('JB') { jbuilder_test(posts) }
end

puts "with 2000 records"

first2k = posts.take(2000)

Benchmark.bm do |x|
  x.report('AMS') { ams_test(first2k) }
  x.report('Roar') { roar_test(first2k) }
  x.report('RABL') { rabl_test(first2k) }
  x.report('JB') { jbuilder_test(first2k) }
end

results

with 100_000 records
       user     system      total        real
AMS  8.570000   0.220000   8.790000 (  8.966108)
Roar 12.940000   0.250000  13.190000 ( 13.522623)
RABL  3.400000   0.080000   3.480000 (  3.488494)
JB  2.420000   0.040000   2.460000 (  2.479700)
with 2000 records
       user     system      total        real
AMS  0.130000   0.010000   0.140000 (  0.133761)
Roar  0.140000   0.000000   0.140000 (  0.146554)
RABL  0.030000   0.000000   0.030000 (  0.033616)
JB  0.030000   0.000000   0.030000 (  0.025291)