Hash access speed with strings/vs symbols

benchmark.rb

require "benchmark"

string_hash = {}
symbol_hash = {}

(0..50000).map do |i|
  string_hash["key_#{i}"] = i
  symbol_hash[:"key_#{i}"] = i
end

string_accessors = Array.new(100000) { "key_#{rand(50000)}" }
symbol_accessors = Array.new(100000) { :"key_#{rand(50000)}" }

Benchmark.bm do |x|
  x.report("strings") { string_accessors.each { |a| string_hash[a] } }
  x.report("symbols") { symbol_accessors.each { |a| symbol_hash[a] } }
  x.report("strings, set") { string_accessors.each { |a| string_hash[a] = a } }
  x.report("symbols, set") { symbol_accessors.each { |a| symbol_hash[a] = a } }
end

results.txt

       user     system      total        real
strings  0.030000   0.000000   0.030000 (  0.031394)
symbols  0.010000   0.000000   0.010000 (  0.019276)
strings, set  0.040000   0.000000   0.040000 (  0.036649)
symbols, set  0.030000   0.000000   0.030000 (  0.024406)