рассчитать скорость отправки файла в секунду, взяв среднее значение 5 раз отправленных байтов

    static long prevSum = 0;
    static long[] rate = new long[5];
    private static void SpeedPerSec(object o)
    {
        fileProgress fP = (fileProgress)o; //get the form conrtols
        while (busy)    // while sending file is active
        {
            for (int i = 0; i < rate.Length; i++)
            {
                //diff between the sent bytes and prev sent bytes
                rate[i] = (sum - prevSum);
                Thread.Sleep(1000/rate.Length);
            }
            prevSum = sum;
            fP.RateLabel(Convert.ToInt64(rate.Average()));   
            //print the trasnfer rate which take a long value .. it just print the value in MB or KB string
        }
    }

вот код sendFile:

    public static bool busy = false;
    public static Socket client;
    public static int packetSize = 1024*8;
    public static int count = 0;
    public static long fileSize;
    public static long sum = 0;
public static void sendFile(string filePath)
    {
        // run the progres Form
        Thread thFP = new Thread(fpRUN);
        fileProgress fP = new fileProgress("Sending...");
        thFP.Start(fP);

        FileStream fs = new FileStream(filePath, FileMode.Open, FileAccess.Read);
        string fileName = Path.GetFileName(filePath);
        byte[] fileData;
        try
        {
            //sending file name and file size to the server
            busy = true;
            fileSize = fs.Length;
            byte[] fileDetial = null;
            string detail =  fileName + "," + fileSize.ToString();
            fileDetial = Encoding.ASCII.GetBytes(detail);
            client.Send(fileDetial);

            //sending file data to the server

            fileData = new byte[packetSize];
            count = 0;
            sum = 0;

            Thread thSpeed = new Thread(SpeedAndTimeLeft); //*here the thread of SPEED per second method
            thSpeed.Start(fP);
            fP.SizeLabel(fileSize);                     // tell the form the file size
            Thread thClock = new Thread(fP.clock);
            thClock.Start();
            while (sum < fileSize)
            {
                fs.Seek(sum, SeekOrigin.Begin);
                fs.Read(fileData, 0, fileData.Length);
                count = client.Send(fileData, 0, fileData.Length, SocketFlags.None);
                sum += count;
                fP.ProgressBarFileHandler(sum,fileSize);        //progressbar value
                fP.SentLabel(sum, fileSize);                    //tell the form how much sent                }
        }
        finally
        {
            busy = false;
            fs.Close();
            fileData = null;
            MessageBox.Show(string.Format("{0} sent successfully", fileName));
        }
    }