rbx -v == rubinius 2.5.0.n24 (2.1.0 af7eb1b4 2015-01-24 3.5.0 JI) [x86_64-darwin14.0.0]

00-symbol-vs-string-equality.rb

require 'benchmark/ips'

SYM = :magic_key
MYS = :key_magic
STR = 'magic_key'
RTS = 'key_magic'

Benchmark.ips do |x|
  x.config(time: 2, warmup: 1)

  x.report('Symbol#==') do
    SYM == SYM
  end

  x.report('Symbol#!=') do
    SYM == MYS
  end

  x.report('String#==') do
    STR == STR
  end

  x.report('String#!=') do
    STR == RTS
  end

  x.compare!
end

01-results.txt

~ [rb:rbx-2.5.99] » ruby foo.rb
Calculating -------------------------------------
           Symbol#==   222.090k i/100ms
           Symbol#!=   228.315k i/100ms
           String#==   393.554k i/100ms
           String#!=   391.007k i/100ms
-------------------------------------------------
           Symbol#==      7.280M (± 1.7%) i/s -     14.658M
           Symbol#!=      3.225M (± 1.8%) i/s -      6.621M
           String#==      7.003M (± 2.1%) i/s -     14.168M
           String#!=      7.207M (± 1.4%) i/s -     14.467M

Comparison:
           Symbol#==:  7279570.8 i/s
           String#!=:  7207471.8 i/s - 1.01x slower
           String#==:  7002508.7 i/s - 1.04x slower
           Symbol#!=:  3225177.3 i/s - 2.26x slower

~ [rb:rbx-2.5.99] » RBXOPT=-Xint ruby foo.rb
Calculating -------------------------------------
           Symbol#==   141.790k i/100ms
           Symbol#!=    86.057k i/100ms
           String#==   148.336k i/100ms
           String#!=   150.662k i/100ms
-------------------------------------------------
           Symbol#==      3.590M (± 3.3%) i/s -      7.231M
           Symbol#!=      1.457M (± 2.3%) i/s -      2.926M
           String#==      4.067M (± 1.2%) i/s -      8.158M
           String#!=      4.123M (± 1.0%) i/s -      8.286M

Comparison:
           String#!=:  4123026.8 i/s
           String#==:  4067338.6 i/s - 1.01x slower
           Symbol#==:  3589855.0 i/s - 1.15x slower
           Symbol#!=:  1456970.2 i/s - 2.83x slower