How to calculate the CPU Usage Programmatically using C# or VB.NET

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The PerformanceCounter class represents a WindowsNT performance counter component. To read from a performance counter, we first create an instance of the PerformanceCounter class supplying the CategoryName, CounterName, and InstanceName as parameters to the constructor and then call the NextValue() method to take a performance counter reading.

Import the namespaces System.Diagnostics and System.Threading.

C#

static PerformanceCounter cpuUsage;
public static void Main(string[] args)
{
    cpuUsage =
        new PerformanceCounter("Processor", "% Processor Time", "_Total");

    Console.WriteLine(cpuUsage.NextValue() + " %");
    Thread.Sleep(1000);
    Console.WriteLine(cpuUsage.NextValue() + " %");
    Console.Read();
}

VB.NET

Private Shared cpuUsage As PerformanceCounter
Public Shared Sub Main(ByVal args() As String)
    cpuUsage = _
    New PerformanceCounter("Processor", "% Processor Time", "_Total")

    Console.WriteLine(cpuUsage.NextValue() & " %")
    Thread.Sleep(1000)
    Console.WriteLine(cpuUsage.NextValue() & " %")
    Console.Read()
End Sub

Note: Observe that we are calling NextValues() twice and after a delay of 1 second. This is because performance counters need two samples to perform the calculation and the counter value is updated once per second, hence the 1 second delay between the two calls.

The output on running this code is as shown below:

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About The Author

Suprotim Agarwal, Developer Technologies MVP (Microsoft Most Valuable Professional) is the founder and contributor for DevCurry, DotNetCurry and SQLServerCurry. He is the Chief Editor of a Developer Magazine called DNC Magazine. He has also authored two Books - 51 Recipes using jQuery with ASP.NET Controls. and The Absolutely Awesome jQuery CookBook.

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