Multithreading Perfomance on PowerShell

These series of tests are meant to understand how well do Linear Loops (foreach) perform against the different multithreading options we have on PowerShell.
The tests consist on first gathering all directories (recursive) from a starting folder ($initialDirectory) and looping through each folder to get the count of all the files.

Tests

• foreach
• Start-Job
• Start-ThreadJob
• Runspace
• ForEach-Object -Parallel

Requirements

• PowerShell v5.1+

Init Variables

• $initialDirectory The initial directory to begin the test, i.e.: C:\user\Documents.
• $numberOfThreads By default is set to 10, this number can be tweaked to get better results.
• $numberOfTestRuns The number of Test Cases we want to perform, by default its set to 5.
• $TestForEachObject By default is set to $true, set to $false if not on PowerShell Core.
• $TestThreadJob By default is set to $true, set to $false if the ThreadJob module is not installed.

Results

• By default, results are sorted by TotalSeconds:

TestRun Test                     TotalSeconds NumberOfFolders NumberOfFiles
------- ----                     ------------ --------------- -------------
      5 RunSpace                    1.4467082            1109         14142
      4 RunSpace                    1.4536342            1109         14142
      3 RunSpace                    1.4733609            1109         14142
      5 Start-ThreadJob             1.4939372            1109         14142
      1 Start-ThreadJob             1.5183739            1109         14142
      2 Start-ThreadJob             1.5588786            1109         14142
      2 RunSpace                    1.5638541            1109         14142
      3 Start-ThreadJob             1.5780027            1109         14142
      4 Start-ThreadJob             1.7246104            1109         14142
      1 RunSpace                    1.8515854            1109         14142
      2 Linear                      1.9031116            1109         14142
      3 Linear                      1.9369417            1109         14142
      5 Linear                      1.9748949            1109         14142
      1 Linear                       2.016238            1109         14142
      4 Linear                      2.6118708            1109         14142
      1 ForEach-Object -Parallel    3.7749827            1109         14142
      4 ForEach-Object -Parallel    3.8035109            1109         14142
      5 ForEach-Object -Parallel    3.8591055            1109         14142
      2 ForEach-Object -Parallel    3.9026964            1109         14142
      3 ForEach-Object -Parallel    4.7344062            1109         14142
      5 Start-Job                   5.0805633            1109         14142
      4 Start-Job                   5.3252725            1109         14142
      3 Start-Job                   5.4109967            1109         14142
      2 Start-Job                    7.038974            1109         14142
      1 Start-Job                   8.5424708            1109         14142