Type:
Module
Constants:
BENCHMARK_VERSION : "2002-04-25"
CAPTION : Benchmark::Tms::CAPTION

The default caption string (heading above the output times).

FORMAT : Benchmark::Tms::FORMAT

The default format string used to display times. See also Benchmark::Tms#format.

The Benchmark module provides methods to measure and report the time used to execute Ruby code.

  • Measure the time to construct the string given by the expression "a"*1_000_000:

    require 'benchmark'
    
    puts Benchmark.measure { "a"*1_000_000 }
    

    On my machine (FreeBSD 3.2 on P5, 100MHz) this generates:

    1.166667   0.050000   1.216667 (  0.571355)

    This report shows the user CPU time, system CPU time, the sum of the user and system CPU times, and the elapsed real time. The unit of time is seconds.

  • Do some experiments sequentially using the bm method:

    require 'benchmark'
    
    n = 50000
    Benchmark.bm do |x|
      x.report { for i in 1..n; a = "1"; end }
      x.report { n.times do   ; a = "1"; end }
      x.report { 1.upto(n) do ; a = "1"; end }
    end
    

    The result:

        user     system      total        real
    1.033333   0.016667   1.016667 (  0.492106)
    1.483333   0.000000   1.483333 (  0.694605)
    1.516667   0.000000   1.516667 (  0.711077)
  • Continuing the previous example, put a label in each report:

    require 'benchmark'
    
    n = 50000
    Benchmark.bm(7) do |x|
      x.report("for:")   { for i in 1..n; a = "1"; end }
      x.report("times:") { n.times do   ; a = "1"; end }
      x.report("upto:")  { 1.upto(n) do ; a = "1"; end }
    end
    

The result:

             user     system      total        real
for:     1.050000   0.000000   1.050000 (  0.503462)
times:   1.533333   0.016667   1.550000 (  0.735473)
upto:    1.500000   0.016667   1.516667 (  0.711239)
  • The times for some benchmarks depend on the order in which items are run. These differences are due to the cost of memory allocation and garbage collection. To avoid these discrepancies, the bmbm method is provided. For example, to compare ways to sort an array of floats:

    require 'benchmark'
    
    array = (1..1000000).map { rand }
    
    Benchmark.bmbm do |x|
      x.report("sort!") { array.dup.sort! }
      x.report("sort")  { array.dup.sort  }
    end
    

    The result:

    Rehearsal -----------------------------------------
    sort!  11.928000   0.010000  11.938000 ( 12.756000)
    sort   13.048000   0.020000  13.068000 ( 13.857000)
    ------------------------------- total: 25.006000sec
    
                user     system      total        real
    sort!  12.959000   0.010000  12.969000 ( 13.793000)
    sort   12.007000   0.000000  12.007000 ( 12.791000)
  • Report statistics of sequential experiments with unique labels, using the benchmark method:

    require 'benchmark'
    include Benchmark         # we need the CAPTION and FORMAT constants
    
    n = 50000
    Benchmark.benchmark(CAPTION, 7, FORMAT, ">total:", ">avg:") do |x|
      tf = x.report("for:")   { for i in 1..n; a = "1"; end }
      tt = x.report("times:") { n.times do   ; a = "1"; end }
      tu = x.report("upto:")  { 1.upto(n) do ; a = "1"; end }
      [tf+tt+tu, (tf+tt+tu)/3]
    end
    

    The result:

                 user     system      total        real
    for:     1.016667   0.016667   1.033333 (  0.485749)
    times:   1.450000   0.016667   1.466667 (  0.681367)
    upto:    1.533333   0.000000   1.533333 (  0.722166)
    >total:  4.000000   0.033333   4.033333 (  1.889282)
    >avg:    1.333333   0.011111   1.344444 (  0.629761)
-
  • References/Ruby on Rails/Ruby/Classes/Benchmark/Benchmark::Tms

-(other) Instance Public methods Returns a new

2025-01-10 15:47:30
benchmark
  • References/Ruby on Rails/Ruby/Classes/Benchmark

benchmark(caption = "", label_width = nil, format = nil, *labels) Class Public methods Invokes

2025-01-10 15:47:30
bm
  • References/Ruby on Rails/Ruby/Classes/Benchmark

bm(label_width = 0, *labels) Class Public methods A simple interface to the

2025-01-10 15:47:30
add!
  • References/Ruby on Rails/Ruby/Classes/Benchmark/Benchmark::Tms

add!(&blk) Instance Public methods An in-place version of

2025-01-10 15:47:30
realtime
  • References/Ruby on Rails/Ruby/Classes/Benchmark

realtime() Class Public methods Returns the elapsed real time used to execute

2025-01-10 15:47:30
to_s
  • References/Ruby on Rails/Ruby/Classes/Benchmark/Benchmark::Tms

to_s() Instance Public methods Same as

2025-01-10 15:47:30
measure
  • References/Ruby on Rails/Ruby/Classes/Benchmark

measure(label = "") Class Public methods Returns the time used to execute the

2025-01-10 15:47:30
add
  • References/Ruby on Rails/Ruby/Classes/Benchmark/Benchmark::Tms

add() Instance Public methods Returns a new

2025-01-10 15:47:30
bmbm
  • References/Ruby on Rails/Ruby/Classes/Benchmark

bmbm(width = 0) Class Public methods Sometimes benchmark results are skewed

2025-01-10 15:47:30
*
  • References/Ruby on Rails/Ruby/Classes/Benchmark/Benchmark::Tms

*(x) Instance Public methods Returns a new

2025-01-10 15:47:30