test.rb

require 'benchmark'
times = 500000
def gen_string
  rand(1<<100).to_s(36)
end

Benchmark.bm(100) do |x|
  x.report('hashes') {
    stringhash = {}
    strings = []
    times.times do 
      strings << gen_string
      stringhash[strings.last.hash] ||= 0
      stringhash[strings.last.hash] += 1
    end
    strings.each do |string|
      stringhash[string.hash] += 1
    end
  }
  x.report('strings') {
    stringhash = {}
    strings = []
    times.times do 
      strings << gen_string
      stringhash[strings.last] ||= 0
      stringhash[strings.last] += 1
    end
    strings.each do |string|
      stringhash[string] += 1
    end
  }
end