PowerShell Where/Filter Speed Test

SpeedTest.ps1

# Get lots of items into an Array
Write-Host 'Getting all files in $env:windir\system32'
$AllFiles = Get-ChildItem -File -Path ($env:windir+"\system32") -Recurse -ErrorAction SilentlyContinue

Write-Host "Found $($AllFiles.Count) files`n"

$Types = @(
    "Simple Match",
    "Where-Object Property"
    "Where-Object ScriptBlock"
    "Filter"
    "Where Method"
    "ForEach"
    "ForEach-Object"
)

$Output = [System.Collections.Generic.List[pscustomobject]]::new()

ForEach ($Type in $Types) {
    switch ($Type) {
        "Simple Match" {
            Write-Output 'Test: $AllFiles -match "cmd.exe"'
            $TimeResult = Measure-Command {
                $Files = $AllFiles -match "cmd.exe"
            }
        }
        "Where-Object Property" {
            Write-Output 'Test: $AllFiles | Where-Object name -match "cmd.exe"'
            $TimeResult = Measure-Command {
                $Files = $AllFiles | Where-Object name -match "cmd.exe"
            }
        }
        "Where-Object ScriptBlock" {
            Write-Output 'Test: $AllFiles | Where-Object { $_.name -match "cmd.exe" }'
            $TimeResult = Measure-Command {
                $Files = $AllFiles | Where-Object { $_.name -match "cmd.exe" }
            }
        }
        "Filter" {
            Write-Output 'Test: filter MyFilter { if ($_ -match "cmd.exe") { $_ } }; $AllFiles | MyFilter'
            $TimeResult = Measure-Command {
                filter MyFilter { if ($_ -match "cmd.exe") { $_ } }
                $Files = $AllFiles | MyFilter
            }
        }
        "Where Method" {
            Write-Output 'Test: $AllFiles.Where({$_.name -match "cmd.exe"})'
            $TimeResult = Measure-Command {
                $Files = $AllFiles.Where({$_.name -match "cmd.exe"})
            }
        }
        "ForEach" {
            Write-Output 'Test: foreach ($file in $AllFiles) { if ($File.name -match "cmd.exe") { $_ } }'
            $TimeResult = Measure-Command {
                $Files = foreach ($File in $AllFiles) {
                    if ($File.name -match "cmd.exe") { $File }
                }
            }
        }
        "ForEach-Object" {
            Write-Output 'Test: $AllFiles | ForEach-Object { if ($_.name -match "cmd.exe") { $_ } }'
            $TimeResult = Measure-Command {
                $Files = $AllFiles | ForEach-Object {
                    if ($_.name -match "cmd.exe") { $_ }
                }
            }
        }
    }
    $Output.Add([pscustomobject]@{
        "Method" = $Type
        "TotalMilliseconds" = [math]::Round($TimeResult.TotalMilliseconds,2)
        "Matching Files" = $Files.Count
    })
}

$Output | Sort-Object -Property TotalMilliseconds