PowerShell: Measure Copy Performance

powershell_measure_copy_performance.ps1

#Requires -Version 5.1
# Reference: 1) https://docs.microsoft.com/en-us/dotnet/api/system.collections.arraylist
# Reference: 2) https://docs.microsoft.com/en-us/dotnet/api/system.diagnostics.stopwatch
# Reference: 3) https://docs.microsoft.com/en-us/dotnet/api/system.io.filestream

# Example 1: Copy file and measure combined (read & write) transfer rate over time
$FilePath = ""      # Path of the file to copy
$Destination= ""    # Path to the new directory or folder
$BufferSize = 64    # Buffer size, in KB, for copying file

$Buffer = [byte[]]::New(1024 * $BufferSize)
$CumulativeBytes = [Collections.Generic.List[int32]]::New()
$CumulativeTicks = [Collections.Generic.List[int64]]::New()
$Stopwatch = [Diagnostics.Stopwatch]::New()

$NewPath = Join-Path -Path $Destination -ChildPath (Split-Path -Path $FilePath -Leaf)
if ($InStream = [IO.File]::OpenRead($FilePath)) {
    if ($OutStream = [IO.File]::Create($NewPath)) {
        $Stopwatch.Start()
        while ($BytesRead = $InStream.Read($Buffer, 0, $Buffer.Length)) {
            $OutStream.Write($Buffer, 0, $BytesRead)
            $CumulativeTicks.Add($Stopwatch.ElapsedTicks)
            $CumulativeBytes.Add($OutStream.Length)
        }
        $Stopwatch.Stop()
        $OutStream.Dispose()
    }
    $InStream.Dispose()
}

$AverageMbps = $CumulativeBytes[-1] * 8 / 1MB / 
               ([TimeSpan]$CumulativeTicks[-1]).TotalSeconds

# Example 2: Copy file and measure read & write transfer rates over time
$FilePath = ""      # Path of the file to copy
$Destination= ""    # Path to the new directory or folder
$BufferSize = 64    # Buffer size, in KB, for copying file

$Buffer = [byte[]]::New(1024 * $BufferSize)
$StreamBytes = [Collections.Generic.List[int32]]::New()
$ReadTicks = [Collections.Generic.List[int64]]::New()
$WriteTicks = [Collections.Generic.List[int64]]::New()
$Stopwatch = [Diagnostics.Stopwatch]::New()

$NewPath = Join-Path -Path $Destination -ChildPath (Split-Path -Path $FilePath -Leaf)
if ($InStream = [IO.File]::OpenRead($FilePath)) {
    if ($OutStream = [IO.File]::Create($NewPath)) {
        $Stopwatch.Start()
        while ($BytesRead = $InStream.Read($Buffer, 0, $Buffer.Length)) {
            $Stopwatch.Stop()
            $StreamBytes.Add($BytesRead)
            $ReadTicks.Add($Stopwatch.ElapsedTicks)
            
            $Stopwatch.Reset()
            $Stopwatch.Start()
            $OutStream.Write($Buffer, 0, $BytesRead)
            $Stopwatch.Stop()
            $WriteTicks.Add($Stopwatch.ElapsedTicks)
            
            $Stopwatch.Reset()
            $Stopwatch.Start()
        }
        $Stopwatch.Stop()
        $OutStream.Dispose()
    }
    $InStream.Dispose()
}

$AverageReadMbps = [Linq.Enumerable]::Sum($StreamBytes) * 8 / 1MB /
                   ([TimeSpan][Linq.Enumerable]::Sum($ReadTicks)).TotalSeconds

$AverageWriteMbps = [Linq.Enumerable]::Sum($StreamBytes) * 8 / 1MB /
                    ([TimeSpan][Linq.Enumerable]::Sum($WriteTicks)).TotalSeconds