Benchmark to compare sort_by and sort for an array that contains orderable values within hashes.

bm: sort_by vs. sort

#!/usr/bin/env ruby

require 'benchmark'
max = 100_000

a = []
flip_flop = false
(1..max).each do |i|
  if flip_flop
    a.unshift({c:[i, i+1]})
    flip_flop = false
  else
    a.push({c:[i, i+1]})
    flip_flop = true
  end
end

Benchmark.bmbm do |bm|
  bm.report('sort_by') do
    a.sort_by { |x| x[:c] }
  end
  bm.report('sort') do
    a.sort { |x, y| x[:c] <=> y[:c] }
  end
end

              user     system      total        real
sort_by   0.500000   0.000000   0.500000 (  0.507925)
sort      0.820000   0.000000   0.820000 (  0.819071)

sort starts getting competitive when array size (max) is reduced to ~100.