BinaryFormatter vs. Manual Serializing

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Runtime.Serialization.Formatters.Binary;
using System.IO;

namespace BinaryFormatterVsManualCoding
{
    class Program
    {
        static byte[] getBytesWithBinaryFormatter(Person toSerialize)
        { 
            MemoryStream stream = new MemoryStream();
            BinaryFormatter formatter = new BinaryFormatter();
            formatter.Serialize(stream, toSerialize);
            return stream.ToArray();
        }

        static byte[] getBytesWithManualWrite(Person toSerialize)
        {
            MemoryStream stream = new MemoryStream();
            Person.WriteToStream(toSerialize, stream);
            return stream.ToArray();
        }

        static void testSize(Person toTest)
        {
            byte[] fromBinaryFormatter = getBytesWithBinaryFormatter(toTest);
            Console.WriteLine("\tWith binary formatter: {0} bytes", fromBinaryFormatter.Length);
            byte[] fromManualWrite = getBytesWithManualWrite(toTest);
            Console.WriteLine("\tManual serializing: {0} bytes", fromManualWrite.Length);

        }

        static void testTime(Person toTest, int timesToTest)
        {
            List<byte[]> binaryFormatterResultArrays = new List<byte[]>();
            List<byte[]> manualWritingResultArrays = new List<byte[]>();

            DateTime start = DateTime.Now;
            for (int i = 0; i < timesToTest; ++i )
                binaryFormatterResultArrays.Add(getBytesWithBinaryFormatter(toTest));
            TimeSpan binaryFormatterSerializingTime = DateTime.Now - start;

            Console.WriteLine("\tBinary formatter serializing: {0} seconds", binaryFormatterSerializingTime.TotalSeconds);

            start = DateTime.Now;
            for (int i = 0; i < timesToTest; i++)
                manualWritingResultArrays.Add(getBytesWithManualWrite(toTest) );
            TimeSpan manualSerializingTime = DateTime.Now - start;
            
            Console.WriteLine("\tManual serializing: {0} seconds", manualSerializingTime.TotalSeconds);
            BinaryFormatter formatter = new BinaryFormatter();
            start = DateTime.Now;
            foreach (var next in binaryFormatterResultArrays)
                formatter.Deserialize(new MemoryStream(next));
            TimeSpan binaryFormatterDeserializingTime = DateTime.Now - start;

            Console.WriteLine("\tBinaryFormatter desrializing: {0} seconds", binaryFormatterDeserializingTime.TotalSeconds );

            start = DateTime.Now;
            foreach (var next in manualWritingResultArrays)
                Person.ReadFromStream(new MemoryStream(next));
            TimeSpan manualDeserializingTime = DateTime.Now - start;

            Console.WriteLine("\tManual desrializing: {0} seconds", manualDeserializingTime.TotalSeconds );


        }

        static void addCards(Person where, int howMany)
        {
            for (int i = 0; i < howMany; ++i)
            { 
                where.AddNewCard(new CreditCard(Guid.NewGuid().ToString(), new DateTime(2012, 12, 24 )));
            }
        }

        static void Main(string[] args)
        {
            Person aPerson = new Person("Kate", new DateTime(1986, 2, 1), new CreditCard[] { new CreditCard(Guid.NewGuid().ToString(), new DateTime(2012, 12, 24 )) });
            Console.WriteLine("Size test: 1 card");
            testSize(aPerson);
            Console.WriteLine("Time test: 1 card, 100 000 times");
            testTime(aPerson, 100000);

            addCards(aPerson, 10000);
            Console.WriteLine("Size test: 10 000 cards");
            testSize(aPerson);

            Console.WriteLine("Time test: 10 000 cards, 100 times");
            testTime(aPerson, 100);

            Console.ReadKey();
        }
    }
}