//Using method of clearing with WriteAllText and writing with Stream.Write
// 7262 ms
// 5410 ms
// 7775 ms
// 7151 ms
// 6854 ms
public static void Main(string[] args)
{
    using (FileStream fs = new FileStream(path + "\\Source.txt", FileMode.Open, FileAccess.Read))
    {
        fileToRead = new byte[fs.Length];
        fs.Read(fileToRead, 0, fileToRead.Length);
    }

    System.Diagnostics.Stopwatch watch = new System.Diagnostics.Stopwatch();
    watch.Start();

    while (iteration < 10)
    {
        File.WriteAllText(path + "\\Dest" + iteration.ToString() + ".txt", string.Empty);
        using (Stream file = File.OpenWrite(path + "\\Dest" + iteration.ToString() + ".txt"))
        {
                file.Write(fileToRead, 0, fileToRead.Length);
        }
        iteration++;
    }

    watch.Stop();
    Console.WriteLine("Watch1::Elapsed:" + watch.ElapsedMilliseconds);

    Console.ReadLine();
}

//using File.WriteAllBytes
// 7563 ms
// 7460 ms
// 7741 ms
// 7598 ms
// 7502 ms
public static void Main(string[] args)
{
    using (FileStream fs = new FileStream(path + "\\Source.txt", FileMode.Open, FileAccess.Read))
    {
    fileToRead = new byte[fs.Length];
    fs.Read(fileToRead, 0, fileToRead.Length);
    }

    System.Diagnostics.Stopwatch watch2 = new System.Diagnostics.Stopwatch();
    watch2.Start();

    while (iteration < 10)
    {
    File.WriteAllBytes(path + "\\Dest" + iteration.ToString() + ".txt", fileToRead);
    iteration++;
    }

    watch2.Stop();
    Console.WriteLine("Watch2::Elapsed:" + watch2.ElapsedMilliseconds);
    Console.ReadLine();
}