Powershell - Improving Script Execution Time - powershell

Question

I've got a script which goes out to computer names from a text file and then polls the services on those machines and writes the results back to a text file.
Here's what I currently have set up:
$Computers = Get-Content computername.txt
$Output = Foreach ($Computer in $Computers) {
Write-Output "`n" "Status of $Computer".ToUpper()
Get-WMIobject -Computername $Computer win32_service | Where-Object {$_.startname -ne "LocalSystem" -and $_.startname -ne "localservice" -and $_.startname -notlike "*AUTHORITY*"} | ft name, startname, startmode, state
}
$Output | Out-File ServiceReport.txt
Is there a way to run multiple sessions at once instead of processing this incrementally? IE - send the command to all the systems at once and then receive the response and record appropriately? I've looked in to Invoke-Command and a few other things but have yet to improve time, get results to write back to the file, or get those options working generally.

Answer 1

Get-WMIObject will multi-thread. You just need to give it more than one computer at a time to work with:
$Computers = Get-Content computername.txt
Get-WMIobject -Computername $Computers win32_service |
Where-Object {$_.startname -ne "LocalSystem" -and $_.startname -ne "localservice" -and $_.startname -notlike "*AUTHORITY*"} |
ft PSComputerName, name, startname, startmode, state |
Out-string |
Out-File ServiceReport.txt
You'll lost the ability to have that "Status of $Computer" line before each one but you can make up for it by including the computer name in the selected objects.