Oj performance?

require 'json'
require 'benchmark'
require 'oj'
require 'yajl'

a = {'asdfg'=> 'asdfg', 'qwert'=> 'asdfatqwtrqewt', 'rewqrq'=>543252, 'reqrqwer'=>[143245,1234421]}
j = a.to_json

N = (ARGV[0] || 100000).to_i

Benchmark.bmbm(6) do |x|
#Benchmark.bm do |x|
  x.report('json g') do N.times{|_| a['vczx'] = _; a.to_json} end
  x.report('yajl g') do N.times{|_| a['vczx'] = _; Yajl.dump(a)} end
  x.report('oj   g') do N.times{|_| a['vczx'] = _; Oj.dump(a)} end
  x.report('ojc  g') do N.times{|_| a['vczx'] = _; Oj.dump(a, mode: :compat)} end
  x.report('json p') do N.times{|_| JSON.parse(j)} end
  x.report('yajl p') do N.times{|_| Yajl.load(j)} end
  x.report('oj   g') do N.times{|_| Oj.load(j)} end
  x.report('ojc  g') do N.times{|_| Oj.load(j, mode: :compat)} end
  x.report('ojdocg') do N.times{|_| Oj::Doc.parse(j).fetch} end
end