Group Policy and WMI Filters–Round 2

Sexy Coffee at North Denver and Rosa Parks Way in Portland, Oregon - Wikipedia user Visitor7This is more of a link dump than anything else.  I was asked what I thought of a WMI-related Group Policy change.

I don’t much care for them.

So I know that WMI Filter queries are a bad idea, but didn’t know how to measure that badness until I saw this blog post (WMI filter queries and thoughts on performance) by Martin Binder.

You can enclose your WMI Filter in a PowerShell “Measure-Command” command, and measure it that way.

Measure-Command { for ( $i=1; $i -le 1000; $i++ ) { Get-WmiObject –Query "SELECT Model FROM Win32_ComputerSystem WHERE Model LIKE 'Compaq Presario A%BB%'" } } | Select-Object TotalMilliseconds | Format-List

TotalMilliseconds : 23308.6037

As the command is looping 1000 times, you’d divide by 1000 and get the answer 23 milliseconds.

Group Policy and WMI filtering slowness
Optimizing Group Policy WMI Filters
Introduction to WMI Basics with PowerShell Part 1 (What it is and exploring it with a GUI)