I am creating a script that splits a target folder s files into subfolders of n length, where n is a number specified dynamically. So basically, if Folder A has 9000 files, and I limit the number of files to 1000 per folder, the script would create nine sub-directories inside of Folder A with 1000 files each. Here is working code: param ( [Parameter(Mandatory,Position=0)] [String] $FileList, [Parameter(Mandatory=$false,ValueFromPipelineByPropertyName)] [Int32] $NumFilesPerFolder = 1000, [Parameter(Mandatory=$false,ValueFromPipelineByPropertyName)] [Int32] $FolderNumberPadding = 2 ) $Folders = Get-Content $FileList Set-Location -LiteralPath ([IO.Path]::GetTempPath()) function Move-Files { [CmdletBinding()] param ( [Parameter(Mandatory,Position=0)] [System.Collections.ArrayList] $List, [Parameter(Mandatory)] [Int32] $Index ) $BaseFolder = [System.IO.Path]::GetDirectoryName($List[0]) $DestFolderName = $Index.ToString().PadLeft($FolderNumberPadding, 0 ) $DestFolder = New-Item -Path (Join-Path $BaseFolder $DestFolderName) -Type Directory -Force Move-Item $List -Destination $DestFolder -Force } foreach ($Folder in $Folders) { $Files = Get-ChildItem -LiteralPath $Folder -File -Force $filesidx = 1 $totalidx = $null $groupidx = 0 $FilesToMove = [System.Collections.ArrayList]@() foreach ($File in $Files) { if($null -eq $totalidx){ $totalidx = $Files.Length } if($filesidx -eq 1){ $groupidx++ } $FilesToMove.Add($File) if($filesidx -eq $NumFilesPerFolder){ Move-Files -List $FilesToMove -Index $groupidx $FilesToMove.Clear() $filesidx = 1 }elseif($totalidx -eq 1){ Move-Files -List $FilesToMove -Index $groupidx $FilesToMove.Clear() break }else{ $filesidx++ } $totalidx-- } } Remove-Item $FileList -Force $app = New-Object -ComObject Shell.Application $appwin = $app.Windows() foreach ($window in $appwin) { if($window.Name -eq "File Explorer"){ $window.Refresh() } } Invoke-VBMessageBox "Operation Complete" -Title "Operation Complete" -Icon Information -BoxType OKOnly This code runs reasonably well, but it heavily bottlenecks when actually moving the files with Move-Item. I d like to try and use RoboCopy here, but I am perplexed as to how I can implement it. What I m having trouble with is that the items I need to move are stored in a list (see the Move-Files function), and every item that needs to be moved are all in the same sub-directory. So I can t just do RoboCopy.exe C:Source C:Destination /mov. How can I integrate RoboCopy here to accomplish my goal? I really need multi-threaded performance as this function will be responsible for moving thousands of files around in production on a frequent basis. Any help would be greatly appreciated - please let me know if I can provide more information to further clarify my objective. Thanks for any help at all!