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

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.