Benchmark

bench.rb

require 'csv'
require 'securerandom'
require 'benchmark'

writer = CSV.open('/tmp/out.csv', 'w')
Benchmark.bm 10 do |r|
  r.report "ベンチマーク" do
    1_000_000.times.each do
      writer << [SecureRandom.hex(10), rand(1_000)]
    end
  end
end

# work$ rbenv shell 2.3.6
# work$ ruby work.rb
#                  user     system      total        real
# ベンチマーク       3.790000   0.030000   3.820000 (  3.846696)

# work$ rbenv shell 2.6.0
# work$ ruby work.rb
#                  user     system      total        real
# ベンチマーク       6.320964  10.233759  16.554723 ( 16.583935)