Archive files

Archive a list of files using powershell. Main criteria is speed, intending to compress folder that contain 100,000 or 1,000,000 of files.

Archive files using Compress-Archive with a list of files

Using PowerShell’s builtin Compress-Archive using the pipe.

Get-ChildItem -Path $sourceFolder | Compress-Archive -DestinationPath $targetArchive

Archive files using Compress-Archive with a list of files

Using PowerShell’s builtin Compress-Archive to archive a list of files.

$compress = @{
    LiteralPath = [IO.Directory]::EnumerateFiles($sourceFolder)
    CompressionLevel = "Fastest"
    DestinationPath = $targetArchive

Compress-Archive @compress

Archive files using System.IO.Compression CreateFromDirectory

Using the .net System.IO.Compression.ZipFile.CreateEntryFromFile(). Adds each file separately, but does not close the zip till the end. Using IO.Directory.EnumerateFiles to get list of files, as this appears to be the fastest approach.

Add-Type -AssemblyName System.IO.Compression.FileSystem
$CompressionLevel = [System.IO.Compression.CompressionLevel]::'Optimal'
$Mode = [System.IO.Compression.ZipArchiveMode]::Create 
$zip = [System.IO.Compression.ZipFile]::Open($targetArchive, $Mode)

[IO.Directory]::EnumerateFiles($sourceFolder) | ForEach-Object {
    [System.IO.Compression.ZipFileExtensions]::CreateEntryFromFile($zip, $_, [System.IO.Path]::GetFileName($_), $CompressionLevel)


Archive directory using System.IO.Compression CreateFromDirectory

Using the .net System.IO.Compression.ZipFile.CreateFromDirectory(). Can only compress a folder, not a select list of files.

$CompressionLevel = [System.IO.Compression.CompressionLevel]::'Optimal'
[System.IO.Compression.ZipFile]::CreateFromDirectory($sourceFolder, $targetArchive, $CompressionLevel, $false)

Archive files using 7Zip4Powershell

Using (7Zip4Powershell)[], which uses 7zip. This suffers from closing the zip after each file, adding two files writes the zip twice.

if(-not(get-module -name 7Zip4Powershell -ea:silentlycontinue)){import-module 7Zip4Powershell}
[IO.Directory]::EnumerateFiles($sourceFolder) | ForEach-Object {
    if(Test-Path $targetArchive)
        Compress-7Zip -CompressionLevel 'Ultra' -Format 'Zip'  -ArchiveFileName $targetArchive -Path $_ -Append | Out-Null
        Compress-7Zip -CompressionLevel 'Ultra' -Format 'Zip' -ArchiveFileName $targetArchive -Path $_ | Out-Null

Archive directory using Pscx Write-Zip

Using PSCX[], When tested there was an error with appending, had to add the source folder.

if(-not(get-module -name pscx -ea:silentlycontinue)){import-module pscx}
    #[IO.Directory]::EnumerateFiles($sourceFolder) | ForEach-Object {
    if(Test-Path $targetArchive)
        # There is a bug in Write-Zip -Append
        # SharpZipLib: "Extra data extended Zip64 information length is invalid"
        throw 'Archive already exists, aborting'
        Get-ChildItem $sourceFolder | Write-Zip -IncludeEmptyDirectories -Level 9 -OutputPath "$targetArchive" -EntryPathRoot $sourceFolder


The tests were run using randomly generated files that each contained 100 random GUIDs.

Results for 1000 files

CompressArchivePipe:    00:00:01.8465544 size:3.1 MB
CompressArchive:        00:00:01.5638973 size:3.1 MB
SystemIO ZipDirectory:  00:00:00.5484307 size:3.1 MB
SystemIO ZipFiles:      00:00:00.5789766 size:3.1 MB
7Zip4Powershell:        00:01:53.2336641 size:2.9 MB
PscxWriteZip:           00:00:01.4106449 size:3.1 MB

Results for 10000 files

CompressArchivePipe:    00:00:30.4606795 size:30.6 MB
CompressArchive:        00:00:24.5795881 size:31.4 MB
SystemIO ZipDirectory:  00:00:05.5481622 size:30.6 MB
SystemIO ZipFiles:      00:00:05.7538935 size:30.6 MB
7Zip4Powershell:        00:48:59.5511709 size:29.4 MB
PscxWriteZip:           00:00:14.0603716 size:30.8 MB

Both PSCX and 7Zip require third party tools to function. Performance wise the biggest impact is to ensure that the solution does not open and close the archive for each file added. Using .net System.IO proves to be the fastest approach, its compression rate is comparable to the others.