Question

I’m running a number of scripts using PowerShell V2, and I have noticed a long pause when the console window first loads. What can I do to improve the performance of my scripts?

Thanks, MagicAndi

Answer 1

Other than minimize what you put in your various profile scripts (shown below) there isn’t much you can do:

C:\PS> $profile | fl * -force


AllUsersAllHosts       : C:\Windows\System32\WindowsPowerShell\v1.0\profile.ps1
AllUsersCurrentHost    : C:\Windows\System32\WindowsPowerShell\v1.0\Microsoft.PowerShell_profile.ps1
CurrentUserAllHosts    : C:\Users\hillr\Documents\WindowsPowerShell\profile.ps1
CurrentUserCurrentHost : C:\Users\hillr\Documents\WindowsPowerShell\Microsoft.PowerShell_profile.ps1

One way to check to see if profile scripts are causing the lag is to start powershell using the -noprofile option. If the startup time is different it would be due to your profile scripts. You can use a .NET stopwatch like so:

function TimeThis([scriptblock]$scriptblock, $msg)
{
    if (!$stopWatch)
    {
        $script:stopWatch = new-object System.Diagnostics.StopWatch
    }
    $stopWatch.Reset()
    $stopWatch.Start()
    . $scriptblock
    $stopWatch.Stop()
    if ($msg -eq $null) { $msg = "$scriptblock" }
    "Execution time: $($stopWatch.ElapsedMilliseconds) mS for $msg"
}

. TimeThis {Import-Module $Module -args ~\Pscx.UserPreferences.ps1}

While you could use Measure-Command, it doesn’t show what is executed and you get no command output (only time in a very verbose fashion).

There used to be an issue in earlier CTPs where the installer wouldn’t ngen the PowerShell assemblies and that could cause noticeable load time delays. However I’m pretty sure that has been fixed as of the final 2.0 install (and certainly with PowerShell built into Windows 7 and Windows Server 2008 R2). If the follow dir and its contents exist, you should be ngen’d:

dir 'C:\Windows\assembly\NativeImages_v2.0.50727_32\Microsoft.PowerShel#' -r