When using PowerShell scripts with WinScriptAdv plugin, PowerShell.exe need some time to start, usually near 3-6 seconds.
You can speed up powershell startup if you run this script in PS once.


Source:
http://stackoverflow.com/questions/4208694/how-to-speed-up-startup-of-powershell-in-the-4-0-environment

Before script: powershell.exe is starting near 5 seconds
After script:  powershell.exe is starting near 1.5 seconds 

Run this ps script:

$env:path = [Runtime.InteropServices.RuntimeEnvironment]::GetRuntimeDirectory()
[AppDomain]::CurrentDomain.GetAssemblies() | % {
  if (! $_.location) {continue}
  $Name = Split-Path $_.location -leaf
  Write-Host -ForegroundColor Yellow "NGENing : $Name"
  ngen install $_.location | % {"`t$_"}
}

