C# – Performance Counter Category Names? (C#)

This (somewhat related) question suggests using the System.Diagnostics.Process.TotalProcessorTime and System.Diagnostics.ProcessThread.TotalProcessorTime properties instead, for low overhead and easy implementation.

(Edit: Here's an article explaining how to use the properties, as well.)

Also, it looks like you're not waiting long enough between calls to "_processTimeCounter.NextValue()." As per the documentation, you're supposed to wait at least 1 second. Not sure if that would cause your strange numbers or not.

I already faced this issue in the past. The ProcessName#InstanceNumber pattern for the instance name was clearly a poor choice from Microsoft, you know why :)

So basically you have two choices:

1) Create a new PerformanceCounter instance each time, using your FindSpawnedProcessPerfCounter method.

2) Follow the steps described in KB281884 to change the pattern from ProcessName#InstanceNumber to ProcessName_ProcessID.

The problem of the first solution is that it requires some CPU time to build a new instance each time.

The problem of the second solution is that the registry modification also impacts all programs that are also using this performance counter. And it requires to modify the registry before launching your app.

Last option you have, is to not use Performance counters at all. If you are only interested in the ProcessorTime information, there are some Kernel32 functions you could call using P/Invoke to retrieve it.

EDIT:

The Process class also provides UserProcessorTime and PrivilegedProcessorTime (kernel processor time) properties. Both return a TimeSpan instance (= amount of time), so to retrieve a percentage of processor time, you'll have to do some computation by yourself (involving the refresh period and the processor times).