TestMonitoringTotalAllocatedMemorySize.cs

public static void TestMonitoringTotalAllocatedMemorySize()
{
    AppDomain.MonitoringIsEnabled = true;

    // provoke JIT, static ctors etc (was allocating 1740 bytes with first call)
    var list = new List<string> { "stringA", "stringB" };
    list.Sort(); 
    var temp = new HashSet<string>();

    var currentDomain = AppDomain.CurrentDomain;

    GC.Collect();
    var hashSetBefore = currentDomain.MonitoringTotalAllocatedMemorySize;

    var countersToUse = new [] {1, 5, 10, 25, 50, 100, 250, 500, 1000, 2500, 5000, 10000, 100000, 250000, 500000};
    foreach (var counter in countersToUse)
    {
        var loopCounter = 0;
        for (int i = 0; i < counter; i++)
        {
            var test = new HashSet<string>();
            loopCounter += test.Count;
        }

        Thread.Sleep(10);
        GC.Collect();
        var hashSetAfter = currentDomain.MonitoringTotalAllocatedMemorySize;
        var totalAlloc = hashSetAfter - hashSetBefore;
        Console.WriteLine(
            "HashSet<string>() = {0,8:N2} bytes (Total = {1,12:N0} bytes, Counter = {2,8:N0}), Current = {3,8:N0} bytes",
            (double)totalAlloc / counter, totalAlloc, counter, GC.GetTotalMemory(forceFullCollection: true));
    }
}