Ruby: sum vs inject benchmark

results.txt

Ruby version 2.4.1

Sum of 100 numbers

Warming up --------------------------------------
                 sum   190.410k i/100ms
              inject   184.380k i/100ms
Calculating -------------------------------------
                 sum      3.303M (± 1.5%) i/s -     33.131M in  10.034500s
              inject      3.046M (± 1.7%) i/s -     30.607M in  10.050375s

Comparison:
                 sum:  3302547.9 i/s
              inject:  3046295.6 i/s - 1.08x  slower

---

Sum of 1 000 numbers

Warming up --------------------------------------
                 sum    51.790k i/100ms
              inject    55.931k i/100ms
Calculating -------------------------------------
                 sum    583.830k (± 0.9%) i/s -      5.852M in  10.024782s
              inject    638.967k (± 2.2%) i/s -      6.432M in  10.071645s

Comparison:
              inject:   638966.7 i/s
                 sum:   583829.9 i/s - 1.09x  slower

---

Sum of 10 000 numbers

Warming up --------------------------------------
                 sum     6.183k i/100ms
              inject     7.056k i/100ms
Calculating -------------------------------------
                 sum     63.090k (± 0.8%) i/s -    636.849k in  10.094933s
              inject     71.878k (± 0.9%) i/s -    719.712k in  10.013696s

Comparison:
              inject:    71878.4 i/s
                 sum:    63090.0 i/s - 1.14x  slower

sum.rb

require 'benchmark/ips'

NUMBERS = (1..10_000).to_a

Benchmark.ips do |x|
  x.config(time: 10, warmup: 2)

  x.report('sum') do
    NUMBERS.sum
  end

  x.report('inject') do
    NUMBERS.inject(:+)
  end

  x.compare!
end