Ruby benchmark for String#chars vs String#each_char

benchmark.txt

Rehearsal --------------------------------------------
option1:   0.711160   0.076554   0.787714 (  0.796558)
option2:   0.327121   0.003232   0.330353 (  0.334768)
----------------------------------- total: 1.118067sec

               user     system      total        real
option1:   0.718185   0.075168   0.793353 (  0.802384)
option2:   0.322129   0.001361   0.323490 (  0.325277)

bm.rb

require "benchmark"
require "memory_profiler"

BASES = %w(A G T C)
STRAND_LENGTH = 100
S1 = STRAND_LENGTH.times.map { BASES.sample }.join
S2 = STRAND_LENGTH.times.map { BASES.sample }.join

def option1
  S1.each_char.zip(S2.each_char).count { |a,b| a != b }
end

def option2
  S1.chars.zip(S2.chars).count { |a,b| a != b }
end

# == speed bechmark
n = 10_000
Benchmark.bmbm do |x|
  x.report("option1:") { n.times { option1 } }
  x.report("option2:") { n.times { option2 } }
end
# ==

# == memory benchmark
report1 = MemoryProfiler.report do
  option1
end
#
report2 = MemoryProfiler.report do
  option2
end
# ==

report1.pretty_print(to_file: "./option1.txt")
report2.pretty_print(to_file: "./option2.txt")

option1.txt

Total allocated: 22136 bytes (407 objects)
Total retained:  120 bytes (3 objects)

allocated memory by gem
-----------------------------------
     22136  other

allocated memory by file
-----------------------------------
     14136  bm.rb
      8000  (no name)

allocated memory by location
-----------------------------------
     14136  bm.rb:10
      8000  (no name):0

allocated memory by class
-----------------------------------
      9104  Array
      8000  String
      4568  Fiber
       384  Enumerator
        80  Proc

allocated objects by gem
-----------------------------------
       407  other

allocated objects by file
-----------------------------------
       207  bm.rb
       200  (no name)

allocated objects by location
-----------------------------------
       207  bm.rb:10
       200  (no name):0

allocated objects by class
-----------------------------------
       202  Array
       200  String
         3  Enumerator
         1  Fiber
         1  Proc

retained memory by gem
-----------------------------------
       120  other

retained memory by file
-----------------------------------
       120  (no name)

retained memory by location
-----------------------------------
       120  (no name):0

retained memory by class
-----------------------------------
        80  String
        40  Array

retained objects by gem
-----------------------------------
         3  other

retained objects by file
-----------------------------------
         3  (no name)

retained objects by location
-----------------------------------
         3  (no name):0

retained objects by class
-----------------------------------
         2  String
         1  Array


Allocated String Report
-----------------------------------
        60  "C"
        38  bm.rb:10
        22  (no name):0

        52  "T"
        28  bm.rb:10
        24  (no name):0

        48  "A"
        29  (no name):0
        19  bm.rb:10

        40  "G"
        25  (no name):0
        15  bm.rb:10


Retained String Report
-----------------------------------
         1  "A"
         1  (no name):0

         1  "G"
         1  (no name):0

option2.txt

Total allocated: 13760 bytes (304 objects)
Total retained:  0 bytes (0 objects)

allocated memory by gem
-----------------------------------
     13760  other

allocated memory by file
-----------------------------------
     13760  bm.rb

allocated memory by location
-----------------------------------
     13760  bm.rb:14

allocated memory by class
-----------------------------------
      8000  String
      5760  Array

allocated objects by gem
-----------------------------------
       304  other

allocated objects by file
-----------------------------------
       304  bm.rb

allocated objects by location
-----------------------------------
       304  bm.rb:14

allocated objects by class
-----------------------------------
       200  String
       104  Array

retained memory by gem
-----------------------------------
NO DATA

retained memory by file
-----------------------------------
NO DATA

retained memory by location
-----------------------------------
NO DATA

retained memory by class
-----------------------------------
NO DATA

retained objects by gem
-----------------------------------
NO DATA

retained objects by file
-----------------------------------
NO DATA

retained objects by location
-----------------------------------
NO DATA

retained objects by class
-----------------------------------
NO DATA


Allocated String Report
-----------------------------------
        60  "C"
        60  bm.rb:14

        52  "T"
        52  bm.rb:14

        48  "A"
        48  bm.rb:14

        40  "G"
        40  bm.rb:14


Retained String Report
-----------------------------------