Ruby benchmark for making empty, compare_by_identity Hash with new / literal vs dup

hash_new_vs_dup.rb

# results on ruby 3.2:
#
# Warming up --------------------------------------
#                  new   277.194k i/100ms
#                  dup   394.839k i/100ms
# Calculating -------------------------------------
#                  new      2.754M (± 1.9%) i/s -     13.860M in   5.034959s
#                  dup      4.006M (± 0.8%) i/s -     20.137M in   5.026561s
# 
# Comparison:
#                  dup:  4006345.3 i/s
#                  new:  2753695.8 i/s - 1.45x  (± 0.00) slower

require 'benchmark/ips'

H = {}.tap(&:compare_by_identity)

Benchmark.ips do |x|
  x.report('new') { {}.tap(&:compare_by_identity) }
  x.report('dup') { H.dup }
  x.compare!
end; nil