Calculate CPU-Usage: Code improvement

Question

I'm calculating the CPU usage on several of my servers. But the calculating is very, very slow.

Here is my code so far:

While it <= 5
    Dim myOptions As New ConnectionOptions
    myOptions.Username = _myParameters("user")
    myOptions.Password = _myParameters("password")

    Dim myRoot As String = "\\" & _myParameters("server") & "\root\cimv2"
    Dim myScope As New ManagementScope(myRoot, myOptions)

    Dim myQuery As New ObjectQuery(String.Format("select * from Win32_Processor"))

    Dim mySearcher As New ManagementObjectSearcher(myScope, myQuery)
    Dim myCollection As ManagementObjectCollection = mySearcher.Get

    For Each OS As ManagementObject In myCollection
        values.Add(OS("LoadPercentage"))
    Next

    Threading.Thread.Sleep(100) //Set some time between two calculations
    itCounter += 1
End While

The code hangs every time on

For Each OS As ManagementObject In myCollection

The application loses about 2-3 seconds there. In case of one CPU that is not a problem. But in our case

• Calculate average using 5 reads

  2.5 sec * 5 = 12.5 secs

• Monitoring some 15 CPU's

  12.5 sec * 15 = 3min

3 min between two updates is just too long.

Question: The reason and the solution of this delay?

Note: This code already runs in another thread.

Note2: Eventual C# code is welcome as well

Solution (With many,many thanks to Jon Egerton)

For future viewers, this solution solved it for me:

        Dim logon As New DlaLogon // control used for impersonation
        logon.impersonateValidUser(//Impersonate here using username + password)
        Dim cpuPerformance As New PerformanceCounter()
        cpuPerformance.MachineName = myParameters("server") //myServername
        cpuPerformance.CategoryName = "Processor"
        cpuPerformance.CounterName = "% Processor Time"
        cpuPerformance.InstanceName = "_Total"

        // Calculate average over 5 times
        While it <= 5
            //Add the result to List 'CpuReads'
            //We will calculate the average based on that list
            cpuReads.Add(cpuPerformance.NextValue())
            Threading.Thread.Sleep(500) // sleep for 0.5 sec 
            it += 1
        End While
        it = 0 
        logon.undoImpersonation() // Undo impersonation

I hope it may be of some use

Answer 1

The System.Diagnostics namespace contains the PerformanceCounter which can be used for obtaining information like this without actually impacting the system as it goes.

This answer Gives a nice example.