From Svendsen Tech PowerShell Wiki

Quite often I've found myself wondering what will work faster, given two or more ways of solving a problem. A way to get a clue is to benchmark it. This will allow you to optimize scripts in some cases. Presented here is a PowerShell module called Benchmark which exports the function Measure-These, which will work like a cmdlet, and can be used to measure how long one or more script blocks take to execute the specified number of times.

The module works with PowerShell version 2 and up.

I use Measure-Object to collect data about the processed script blocks, and apparently there is quite a bit of overhead involved in this, so if the measured commands take about 1.1 seconds with 10,000 iterations, you might find the benchmark script itself to take maybe 12 seconds, as in one of my test cases. The overhead seems to increase fast with the number of iterations. I tried rolling my own algorithm instead of using Measure-Object, but failed miserably at improving the performance.

If you prefer to have it as a function in your profile rather than a module, simply copy and paste the entire content of the .psm1 file into your PowerShell profile (external Microsoft site link). You can also dot-source the script file containing the Measure-These function on demand when you need it, but you need to rename the file to have a .ps1 extension as modules pop up in notepad (for "security" reasons) when dot-sourced:





Tweet









Dot-sourcing it on demand:

PS C:\> copy .\Benchmark.psm1 Benchmark.ps1 PS C:\> . .\Benchmark.ps1 PS C:\> Get-Help Measure-These

It's based on Measure-Command, which works like this:

PS E:\> Measure-Command { dir -r e:\temp } | Select -ExpandProperty TotalMilliseconds 223,0757 PS E:\> Measure-Command { dir -r e:\temp } Days : 0 Hours : 0 Minutes : 0 Seconds : 0 Milliseconds : 51 Ticks : 512956 TotalDays : 5,93699074074074E-07 TotalHours : 1,42487777777778E-05 TotalMinutes : 0,000854926666666667 TotalSeconds : 0,0512956 TotalMilliseconds : 51,2956

Download

Benchmark.zip - download, remember to unblock before extracting and unzip into a PowerShell module directory (tip: see $env:PSModulePath - and create a "Modules" directory if necessary). Or install from the PowerShell gallery (see below).

If you have Windows Management Framework 5 or higher (WMF 5 is available for Windows 7 and up), you can install my "Benchmark" module from the PowerShell gallery, a Microsoft-driven project and online repository for scripts.

To install with WMF 5 and up (to get the latest Benchmark module version available), simply run this command (requires an internet connection):

Install-Module -Name Benchmark

or for your user only (no elevation required):

Install-Module -Name Benchmark -Scope CurrentUser

2017-12-02 : Uploaded v1.2.2. Minor doc fixes. Make $Precision a Byte. Use [CmdletBinding()] and add scaffolding.

: Uploaded v1.2.2. Minor doc fixes. Make $Precision a Byte. Use [CmdletBinding()] and add scaffolding. 2017-12-01: Uploaded v1.2.1. Return numerical types for easier use with comparison operators (such as -gt and -lt). Add optional -Precision parameter (default 5). Trailing zeroes are removed (by [Math]::Round()).







Example Screenhots



One with multiple counts specified:





Examples As Text

Let's see how accurate Start-Sleep and the measurement is. Not too bad.

PS C:\> Import-Module Benchmark PS C:\> Measure-These -Count 5 -ScriptBlock { sleep 1 }, { sleep 2 }, { sleep 5 } -Title '1 second', '2 seconds', '5 seconds' | Format-Table -AutoSize Title/no. Average (ms) Count Sum (ms) Maximum (ms) Minimum (ms) --------- ------------ ----- -------- ------------ ------------ 1 second 1,000.06218 5 5,000.31090 1,002.43900 999.41950 2 seconds 1,999.58470 5 9,997.92350 1,999.66930 1,999.53590 5 seconds 4,999.75984 5 24,998.79920 4,999.95170 4,999.67560

Compare some methods of determining if a string is contained within another string. 50,000 iterations. This time around on PSv4, where they appear to have made some optimizations to "-like".

PS C:\temp> $String = 'some target string' PS C:\temp> Measure-These -Count 50000 -ScriptBlock { $String -match 'target' }, { $String.Contains('target') }, { $String -like '*target*' } -Title '-match', '.contains()', '-like' | ft -auto Title/no. Average (ms) Count Sum (ms) Maximum (ms) Minimum (ms) --------- ------------ ----- -------- ------------ ------------ -match 0.03024 50000 1,512.10510 2.80810 0.02630 .contains() 0.02386 50000 1,192.81570 6.16960 0.01950 -like 0.02893 50000 1,446.25670 2.93130 0.02380

Default output with Format-List.

PS C:\> Measure-These -Count 1 { sleep 3 } Title/no. : 1 Average (ms) : 3,000.46310 Count : 1 Sum (ms) : 3,000.46310 Maximum (ms) : 3,000.46310 Minimum (ms) : 3,000.46310 PS C:\>

Assigning the resulting object to a variable.

PS C:\> $TimedSleep = Measure-These -Count 1 { sleep 3 } PS C:\> $TimedSleep Title/no. : 1 Average (ms) : 2,999.98120 Count : 1 Sum (ms) : 2,999.98120 Maximum (ms) : 2,999.98120 Minimum (ms) : 2,999.98120

Source Code

function Measure-These { <# .SYNOPSIS Svendsen Tech's Benchmarking Module for PowerShell. Benchmark PowerShell script blocks and (virtually) any "DOS"/cmd.exe command using this module built around PowerShell's Measure-Command cmdlet. It is designed to give a quick, convenient overview of how code performs when doing for instance the same thing in different ways. See the comprehensive online documentation at: http://www.powershelladmin.com/wiki/PowerShell_benchmarking_module_built_around_Measure-Command MIT license. .DESCRIPTION This is a benchmarking module for PowerShell. Get objects containing data about the execution time of script blocks. Pipe to Format-Table -AutoSize for a direct report. You can also assign the resulting objects to a variable (do not use Format-Table if assigning to a variable). See the comprehensive online documentation at: http://www.powershelladmin.com/wiki/PowerShell_benchmarking_module_built_around_Measure-Command Copyright (c) 2012-2017, Joakim Borger Svendsen. All rights reserved. Author: Joakim Borger Svendsen MIT license. .PARAMETER Count Number of times to execute the code in each specified script block. Pass in multiple counts separated by commas. .PARAMETER ScriptBlock Script block(s) to time the execution time of and collect data about. .PARAMETER Title Optional titles for each script block. Title 1 goes with block 1, 2 with 2, and so on. If you omit titles, you will get numbered script blocks (from left to right). If you have fewer titles than script blocks, you will get numbers when you "run out of titles". .PARAMETER Precision Specify number of digits after the decimal separator. Default 5. Maximum 15. Trailing zeroes are removed by the [Math]::Round() static function. #> [CmdletBinding()] param( [Parameter(Mandatory = $true)] [Int32[]] $Count, [Parameter(Mandatory = $true)] [ScriptBlock[]] $ScriptBlock, [String[]] $Title = @(''), [ValidateRange(1, 15)][Byte] $Precision = 5) begin { } process { $Times = @() $BlockNumber = 0 foreach ($LoopCount in $Count) { $ScriptBlock | ForEach-Object { $Block = $_ $BlockNumber++ $Times += 1..$LoopCount | ForEach-Object { Measure-Command -Expression $Block | # Process the current block once for each specified $Count. Select-Object -ExpandProperty TotalMilliSeconds # Get only the milliseconds. } | # End of 1..$Count ForEach-Object which will be passed to Measure-Object. Measure-Object -Sum -Maximum -Minimum | # Gather results using Measure-Object. ForEach-Object { # Send results down the pipeline in the form of custom PS objects. New-Object -TypeName PSObject -Property @{ 'Average (ms)' = $_.Sum / $_.Count 'Maximum (ms)' = $_.Maximum 'Minimum (ms)' = $_.Minimum 'Count' = $_.Count 'Sum (ms)' = $_.Sum 'BlockNumber' = $BlockNumber } } } # End of $ScriptBlock ForEach-Object } # End of $Count foreach loop } end { # Since this is a _benchmarking_ module, it seems in the right spirit to # cache this for a performance gain. :) $NumBlocks = $ScriptBlock.Count # This is used to keep track of the relative position in the block count. # Had to script scope it or else I think it behaved sort of like a closure # inside the Select-Object below. $Script:Counter = 0 $Times | Select-Object @{n='Title/no.'; e={ ++$script:Counter $Index = $script:Counter - 1 if ($script:Counter -ge $NumBlocks) { $script:Counter = 0 } if ($Title[$Index]) { $Title[$Index] } else { $_.BlockNumber } }}, @{ Name = 'Average (ms)'; Expression = { [Math]::Round($_.'Average (ms)', $Precision)} }, Count, @{ Name = 'Sum (ms)'; Expression = { [Math]::Round($_.'Sum (ms)', $Precision) } }, @{ Name = 'Maximum (ms)'; Expression = { [Math]::Round($_.'Maximum (ms)', $Precision) } }, @{ Name = 'Minimum (ms)'; Expression = { [Math]::Round($_.'Minimum (ms)', $Precision) } } } }