Struct vs Class with GC overhead

using System;
using System.Collections.Generic;
using System.Diagnostics;
struct MyStruct
{
    public int Id;
    public string Name;
    public DateTime DateOfBirth;
    public string Comment;
}
class MyClass
{
    public int Id { get; set; }
    public string Name { get; set; }
    public DateTime DateOfBirth { get; set; }
    public string Comment { get; set; }
}
static class Program
{
    static void Main()
    {
        var dob = DateTime.Today;

        const int SIZE = 1 * 1000 * 1000;
        const int REPEATS = 100 * 1000 * 1000;

        Stopwatch watch = Stopwatch.StartNew();
        var s = new MyStruct[SIZE];
        for (int i = 0; i < REPEATS; i++)
        {
            s[i % SIZE] = new MyStruct
            {
                Comment = "abc", DateOfBirth = dob,
                Id = 123, Name = "def"
            };
        }
        watch.Stop();
        Console.WriteLine("struct/field: "
                  + watch.ElapsedMilliseconds + "ms");

        watch = Stopwatch.StartNew();
        var c = new MyClass[SIZE];
        for (int i = 0; i < REPEATS; i++)
        {
            c[i % SIZE] = new MyClass
            {
                Comment = "abc", DateOfBirth = dob,
                Id = 123, Name = "def"
            };
        }
        watch.Stop();
        Console.WriteLine("class/property: "
                   + watch.ElapsedMilliseconds + "ms");
        Console.ReadLine();
    }
}