Hash access speed with strings/vs symbols

benchmark.rb

require "benchmark"

hash = {'key' => 1, :key => 2}

n = 5_000_000

Benchmark.bm do |x|
  x.report("strings") { n.times { hash['key'] } }
  x.report("symbols") { n.times { hash[:key]  } }
  x.report("strings, set") { n.times { hash['key'] = 1 } }
  x.report("symbols, set") { n.times { hash[:key]  = 1 } }
end

results.txt

       user     system      total        real
strings  1.040000   0.010000   1.050000 (  1.044701)
symbols  0.460000   0.000000   0.460000 (  0.461030)
strings, set  1.250000   0.000000   1.250000 (  1.253017)
symbols, set  0.690000   0.000000   0.690000 (  0.689607)

I think removing the hash ops speaks for itself. It's all about the string allocation and symbol table searching.

Benchmark.bm do |x|
  x.report("strings") { n.times { 'key' } }
  x.report("symbols") { n.times { :key } }
end

user system total real
strings 1.170000 0.000000 1.170000 ( 1.172716)
symbols 0.310000 0.000000 0.310000 ( 0.316076)