2 comments

1. If you use a stopwatch the results for m6 will be a lot different (at least a factor of 10), see the gist I created below with a little modified code.

   
   

   	$iterations = 10000
   	$saveFile = 'C:\Users\heman\Desktop\OverheadTests\results.txt'
   	$m1Description = 'Refence: Only doing calculations'
   	Write-Host 'Starting Measurement 1'
   	$m1 = Measure-Command {
   	1..100 | ForEach-Object {
   	$_ + ($_ * $_)
   	}
   	}
   	$m2Description = 'Using Write-Host to output result of calculation to the host'
   	Write-Host 'Starting Measurement 2'
   	$m2 = Measure-Command {
   	1..$iterations | ForEach-Object {
   	Write-Host "Result of calculation: $($_ + ($_ * $_))"
   	}
   	}
   	$m3Description = 'Using Write-Output to output result of calculation'
   	Write-Host 'Starting Measurement 3'
   	$m3 = Measure-Command {
   	1..$iterations | ForEach-Object {
   	Write-Output "Result of calculation: $($_ + ($_ * $_))"
   	}
   	}
   	$m4Description = 'Saving result of calculation to an Array'
   	Write-Host 'Starting Measurement 4'
   	$m4 = Measure-Command {
   	$result = @()
   	1..$iterations | ForEach-Object {
   	$result += $_ + ($_ * $_)
   	}
   	}
   	$m5Description = 'Saving result of calculation to an ArrayList'
   	Write-Host 'Starting Measurement 5'
   	$m5 = Measure-Command {
   	$resultAL = New-Object System.Collections.ArrayList
   	1..$iterations | ForEach-Object {
   	[void]$resultAL.Add(($_ + ($_ * $_)))
   	}
   	}
   	$m6Description = 'Using Write-Progress to output result of calculation'
   	Write-Host 'Starting Measurement 6'
   	$count = 0
   	$m6 = Measure-Command {
   	$sw = [System.Diagnostics.Stopwatch]::StartNew()
   	1..$iterations | ForEach-Object {
   	$count++
   	if ($sw.Elapsed.TotalMilliseconds -ge 500){
   	Write-Progress -Activity 'Processing' -CurrentOperation "Result: $($_ + ($_ * $_))" -PercentComplete (($count / $iterations * 100))
   	$sw.Reset();
   	$sw.Start();
   	}
   	}
   	}
   	$m7Description = 'Save result of calculation to file, write per iteration'
   	Write-Host 'Starting Measurement 7'
   	$m7 = Measure-Command {
   	1..$iterations | ForEach-Object {
   	$result = $_ + ($_ * $_)
   	$result | Out-File -FilePath $saveFile -Append
   	}
   	}
   	Remove-Item -Path $saveFile -Force
   	$m8Description = 'Save result of calculation to file, write when done (using ArrayList to store results)'
   	Write-Host 'Starting Measurement 8'
   	$m8 = Measure-Command {
   	$resultAL = New-Object System.Collections.ArrayList
   	1..$iterations | ForEach-Object {
   	[void]$resultAL.Add(($_ + ($_ * $_)))
   	}
   	$resultAL | Out-File -FilePath $saveFile -Append
   	}
   	Remove-Item -Path $saveFile -Force
   	Write-Host 'Finished all measurements'
   	Write-Host ''
   	Write-Output ([PSCustomObject] [Ordered] @{
   	Milliseconds = [math]::Round($m1.TotalMilliseconds)
   	Description = $m1Description
   	})
   	Write-Output ([PSCustomObject] [Ordered] @{
   	Milliseconds = [math]::Round($m2.TotalMilliseconds)
   	Description = $m2Description
   	})
   	Write-Output ([PSCustomObject] [Ordered] @{
   	Milliseconds = [math]::Round($m3.TotalMilliseconds)
   	Description = $m3Description
   	})
   	Write-Output ([PSCustomObject] [Ordered] @{
   	Milliseconds = [math]::Round($m4.TotalMilliseconds)
   	Description = $m4Description
   	})
   	Write-Output ([PSCustomObject] [Ordered] @{
   	Milliseconds = [math]::Round($m5.TotalMilliseconds)
   	Description = $m5Description
   	})
   	Write-Output ([PSCustomObject] [Ordered] @{
   	Milliseconds = [math]::Round($m6.TotalMilliseconds)
   	Description = $m6Description
   	})
   	Write-Output ([PSCustomObject] [Ordered] @{
   	Milliseconds = [math]::Round($m7.TotalMilliseconds)
   	Description = $m7Description
   	})
   	Write-Output ([PSCustomObject] [Ordered] @{
   	Milliseconds = [math]::Round($m8.TotalMilliseconds)
   	Description = $m8Description
   	})

   view raw
   
   overheadtest_alittletuned.ps1
   
   hosted with ❤ by GitHub

   This was a learning that I came across a few months ago when working on some issues with write-progress slowing down some file operations and saw the following SO answer:
   http://stackoverflow.com/questions/21304282/how-to-improve-the-performance-of-write-progress

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   1. Thanks for the feedback! That is actually a very good “solution” to the problem of overhead when using Write-Progress! Thanks!

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