Ruby benchmark `SecureRandom.hex(16)` vs `SecureRandom.uuid`

request_id.rb

#!/usr/bin/env ruby
# frozen_string_literal: true

require "benchmark/ips"
require "securerandom"

Benchmark.ips do |x|
  x.report("hex(16)") { SecureRandom.hex(16) }
  x.report("uuid") { SecureRandom.uuid }
  x.compare!
end

__END__
Result:

  Warming up --------------------------------------
               hex(16)    38.576k i/100ms
                  uuid    16.630k i/100ms
  Calculating -------------------------------------
               hex(16)    439.159k (±15.0%) i/s -      2.083M in   5.037059s
                  uuid    184.132k (± 9.1%) i/s -    931.280k in   5.109522s

  Comparison:
               hex(16):   439159.0 i/s
                  uuid:   184132.3 i/s - 2.39x  slower
Ruby:

    ruby 2.4.2p198 (2017-09-14 revision 59899) [x86_64-darwin16]

Hardware:

    Hardware Overview:

      Model Name: MacBook Pro
      Model Identifier: MacBookPro12,1
      Processor Name: Intel Core i7
      Processor Speed: 3,1 GHz
      Number of Processors: 1
      Total Number of Cores: 2
      L2 Cache (per Core): 256 KB
      L3 Cache: 4 MB
      Memory: 16 GB
      Boot ROM Version: MBP121.0171.B00
      SMC Version (system): 2.28f7

Software:

    System Software Overview:

      System Version: macOS 10.12.6 (16G1036)
      Kernel Version: Darwin 16.7.0
      Time since boot: 25 days 10:55