Question

How do I calculate the private working set of memory using C#? I’m interested in producing roughly the same figures as taskmgr.exe.

I’m using the Process namespace and using methods/data like WorkingSet64 and PrivateMemorySize64, but these figures are off by 100MB or more at times.

Answer 1

This is a highly variable number, you cannot calculate it. The Windows memory manager constantly swaps pages in and out of RAM. TaskMgr.exe gets it from a performance counter. You can get the same number like this:

using System;
using System.Diagnostics;

class Program {
    static void Main(string[] args) {
        string prcName = Process.GetCurrentProcess().ProcessName;
        var counter = new PerformanceCounter("Process", "Working Set - Private", prcName);
        Console.WriteLine("{0}K", counter.RawValue / 1024);
        Console.ReadLine();
    }
}

Do beware that the number really doesn’t mean much, it will drop when other processes get started and compete for RAM.