Redundant Object.ToString

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Threading.Tasks;

namespace Redundant_Object.ToString
{
    class Program
    {

        static void Main(string[] args)
        {
            doTest();
            Console.ReadLine();
        }

        private static async void doTest()
        {
            TimeSpan test1 = new TimeSpan();
            TimeSpan test2 = new TimeSpan();
            TimeSpan test3 = new TimeSpan();
            TimeSpan test4 = new TimeSpan();

            for (int x = 0; x < 100; x++)
            {

                test1 += await Task.Factory.StartNew<TimeSpan>(() =>
                            {
                                Stopwatch sw = new Stopwatch();
                                sw.Start();

                                MakeKeyToString(1, "Ashley", "MyBrand");

                                sw.Stop();
                                return sw.Elapsed;
                            });
            }



            for (int x = 0; x < 100; x++)
            {

                test2 += await Task.Factory.StartNew<TimeSpan>(() =>
                {
                    Stopwatch sw = new Stopwatch();
                    sw.Start();

                    MakeKey(1, "Ashley", "MyBrand");

                    sw.Stop();
                    return sw.Elapsed;
                });
            }

            for (int x = 0; x < 100; x++)
            {

                test3 += await Task.Factory.StartNew<TimeSpan>(() =>
                {
                    Stopwatch sw = new Stopwatch();
                    sw.Start();

                    NullMakeKeyToString(1, "Ashley", "MyBrand");

                    sw.Stop();
                    return sw.Elapsed;
                });
            }

            for (int x = 0; x < 100; x++)
            {

                test4 += await Task.Factory.StartNew<TimeSpan>(() =>
                {
                    Stopwatch sw = new Stopwatch();
                    sw.Start();

                    NullMakeKey(1, "Ashley", "MyBrand");

                    sw.Stop();
                    return sw.Elapsed;
                });
            }

            Console.WriteLine("With ToString: " + test1.TotalMilliseconds / 100);
            Console.WriteLine("Without ToString: " + test2.TotalMilliseconds / 100);
            Console.WriteLine("Nullable int With ToString: " + test3.TotalMilliseconds / 100);
            Console.WriteLine("Nullable int Without ToString: " + test4.TotalMilliseconds / 100);
        }

        private static string MakeKeyToString(int SnapshotID, string UserName, string BrandName)
        {
            return string.Format("{0}:{1}:{2}", SnapshotID.ToString(), UserName, BrandName);
        }

        private static string MakeKey(int SnapshotID, string UserName, string BrandName)
        {
            return string.Format("{0}:{1}:{2}", SnapshotID, UserName, BrandName);
        }

        private static string NullMakeKeyToString(int? SnapshotID, string UserName, string BrandName)
        {
            return string.Format("{0}:{1}:{2}", SnapshotID.ToString(), UserName, BrandName);
        }

        private static string NullMakeKey(int? SnapshotID, string UserName, string BrandName)
        {
            return string.Format("{0}:{1}:{2}", SnapshotID, UserName, BrandName);
        }

    }
}