I'm new to using Perfmon and performance monitoring in general (so go easy on me please ;)

I know that Perfmon doesn't have anything exactly like Task Manager's CPU usage display, but I'm trying to figure out how to monitor user's CPU usage via Perfmon in a similar way, and trying to understand the measurements (or how to convert the numbers to get a similar understanding)

For example, if in Task Manager, a particular user is consistently using more than 5% CPU, I would want to contact the user about it.

I learn best by example, so here is exactly what I'm trying to do, with a specific example:

This is for a 32-bit Dual Quad Core Windows 2003 web server (8 CPUs), there are many web sites on the server, each running within their own application pool/worker process ID.

Through other research here I learned of a registry change that I made so that the PID shows up with the w3wp process so I can easily identify the site later by cross-referencing it.

I set up a counter with the following settings:

Process -> % Processor Time  -> all instances

Here is an example. Say I'm interested in "black line" user in this graph below, as his process is spiking quite high compared to all the other users:

(I wasn't allowed to post the image as I'm a new user on this site.. I've uploaded the image to:)


So... using this as an example, I see that they have an AVERAGE % PROCESSOR TIME of 23.264 , and have spiked as high as 103.124

So what exactly does this 23.264 number mean to me? Is it similar to an average of Task Manager's CPU reading for this user?

Or, since this server has 8 CPUs, should I divide this number by 8? (23.264/8 = 2.9% AVERAGE CPU LOAD?)

Thanks in advance.

2 Answers 2


Most people tend not to watch processor time but instead Processor Queue Length (number of threads waiting for a processor).

That being said there's a good explanation here:


  • That's a good article, and he does mention Processor Time there as well. Remember that for my needs I need to be able to see the usage of the w3wp processes, I don't know of any other way to get it to report on w3wp processes, other than using counters under the Processors section. I think what I'm doing so far can work (I think?), but I just don't have a good understanding of what the numbers actually mean, comparing to what I'm used to (task manager's cpu usage) Thanks
    – nat
    Nov 12, 2009 at 0:55

I know this question is bit old but another related discussion is found here:

Perfmon Process: % Processor Time vs. Task Manager’s CPU usage

The main point is that you also need to capture "processor\% user time" and multiply that by the "process\% processor time" of the process you are interested in.

I personally think you should include the "processor\% privilege time" since "process\% processor time" includes both "process\% user time" and "process\% privilege time" but don't take my word for it on that.

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