Output suppression and the pipeline

Test-NullPerformance.ps1

<#
.Synopsis

   Performance test for output suppression in PowerShell
.DESCRIPTION

   Very basic performance test against different types of output suppression in PowerShell
   Increase the value of the Iterations parameter to observe how performance impacts the different methods

   
   SPOILER ALERT: Piping to Out-Null starts to stagger as input collection increases in size, because it processes each item individually

   Warning: This script writes all output directly to the host, sorry puppies
.EXAMPLE

   .\Test-NullPerformance.ps1
.EXAMPLE

   .\Test-NullPerformance.ps1 -Iterations 1000
.EXAMPLE

   10,100,1000,10000 |ForEach-Object { .\Test-NullPerformance.ps1 -Iterations $_ }
.EXAMPLE

   for($i = 1; $i -lt 1000000; $i *= 2) { 
     .\Test-NullPerformance.ps1 -Iterations $i
   }
.NOTES
   Author: Mathias R. Jessen (@IISResetMe), April 2015
#>

param(
    [Parameter(Mandatory=$false,ValueFromPipeline=$true)] 
    [ValidateRange(1,10000000)]
    [int]$Iterations = 100000
    )

Write-Host "Suppressing $Iterations integers..." -ForegroundColor Green

$StopWatch = [System.Diagnostics.Stopwatch]::StartNew()

Write-Host "Pipe to Out-Null:   " -NoNewline
$StopWatch.Restart()
1..$Iterations | Out-Null
Write-Host $StopWatch.ElapsedMilliseconds

Write-Host "Assign to `$null:    " -NoNewline
$StopWatch.Restart()
$null = 1..$Iterations
Write-Host $StopWatch.ElapsedMilliseconds

Write-Host "Redirect to `$null:  " -NoNewline
$StopWatch.Restart()
1..$Iterations > $null
Write-Host $StopWatch.ElapsedMilliseconds

Write-Host "Cast to void:       " -NoNewline
$StopWatch.Restart()
[void]( 1..$Iterations )
Write-Host $StopWatch.ElapsedMilliseconds

Write-Host "Cast as void:       " -NoNewline
$StopWatch.Restart()
( 1..$Iterations ) -as [void]
Write-Host $StopWatch.ElapsedMilliseconds

$StopWatch.Stop()