CPU Usage in Task Manager using Performance Counters

Question

[My Attempts]

Already went through

1. How to get the CPU Usage in C#? But \"_Total\" Instance of Processor would give me total consumption of CPU as o

Answer 1

If you use this, you can get the same result with the task manager :

cpuCounter = new PerformanceCounter(
        "Processor Information",
        "% Processor Utility",
        "_Total",
        true
    );

Answer 2

This gives me the exact figure you get on Task Manager (in the Details tab), is this what you want?

// Declare the counter somewhere
var process_cpu = new PerformanceCounter(
                                   "Process", 
                                   "% Processor Time", 
                                   Process.GetCurrentProcess().ProcessName
                                        );
// Read periodically
var processUsage = process_cpu.NextValue() / Environment.ProcessorCount;

Answer 3

After reading this performance counter document https://social.technet.microsoft.com/wiki/contents/articles/12984.understanding-processor-processor-time-and-process-processor-time.aspx I realized that the correct approach to getting this value is actually to take 100 and subtract the idle time of all processors.

% Processor Time is the percentage of elapsed time that the processor spends to execute a non-Idle thread.

var allIdle = new PerformanceCounter(
    "Processor", 
    "% Idle Time", 
    "_Total"
);

int cpu = 100 - allIdle;

This gives a value very close to what Task Manager displays and perhaps is only different at some points due to rounding or the specific time of when the counter is polled.