Side-By-Side comparison for TPL and Sequential out of band calls

Program.cs

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

namespace ConsoleApplication34
{
    class Program
    {
        static void Main(string[] args)
        {
            Sequential();
            TLP();
        }

        private static void TLP()
        {
            Console.WriteLine("\r\nUsing Task Parallelism");
            Stopwatch stopwatch = new Stopwatch();
            stopwatch.Start();
            DataService dataService = new DataService();

            Task<IDictionary<int, string>> data01 = Task.Factory.StartNew(() => dataService.GetData(numberOfPeople: 2));
            Task<IDictionary<int, string>> data02 = Task.Factory.StartNew(() => dataService.GetData(numberOfPeople: 3));
            Task<IDictionary<int, string>> data03 = Task.Factory.StartNew(() => dataService.GetData(numberOfPeople: 3));
            Task<IDictionary<int, string>> data04 = Task.Factory.StartNew(() => dataService.GetData(numberOfPeople: 4));
            Task<IDictionary<int, string>> data05 = Task.Factory.StartNew(() => dataService.GetData(numberOfPeople: 5));

            Task.WaitAll(data01, data02, data03, data04, data05);

            var q = from d1 in data01.Result
                    join d2 in data02.Result on d1.Key equals d2.Key
                    join d3 in data03.Result on d2.Key equals d3.Key
                    join d4 in data04.Result on d2.Key equals d4.Key
                    join d5 in data04.Result on d2.Key equals d5.Key
                    select new { Name = d1.Value };

            Console.WriteLine(" {{some arbitrary result}} » User Count {0}", q.Count());
            Console.WriteLine(" ElapsedMilliseconds » {0}", stopwatch.ElapsedMilliseconds);
        }

        private static void Sequential()
        {
            Console.WriteLine("\r\nUsing Sequential Calls");
            Stopwatch stopwatch = new Stopwatch();
            stopwatch.Start();
            DataService dataService = new DataService();

            var q = from d1 in dataService.GetData(numberOfPeople: 2)
                    join d2 in dataService.GetData(numberOfPeople: 3) on d1.Key equals d2.Key
                    join d3 in dataService.GetData(numberOfPeople: 3) on d1.Key equals d3.Key
                    join d4 in dataService.GetData(numberOfPeople: 4) on d1.Key equals d4.Key
                    join d5 in dataService.GetData(numberOfPeople: 5) on d1.Key equals d5.Key
                    select new { Name = d1.Value };

            Console.WriteLine(" {{some arbitrary result}} » User Count {0}", q.Count());
            Console.WriteLine(" ElapsedMilliseconds » {0}", stopwatch.ElapsedMilliseconds);
        }
    }

    public class DataService
    {
        private readonly Dictionary<int, string> _names = new Dictionary<int, string> { { 1, "John" }, { 2, "Paul" }, { 3, "George" }, { 4, "Ringo" } };
        private Guid _id;

        public DataService()
        {
            _id = Guid.NewGuid();
        }

        public IDictionary<int, string> GetData(int numberOfPeople = 0)
        {
            Console.WriteLine(" Fetching {0} users (class {1} / method instance {2})", numberOfPeople, _id, Guid.NewGuid());
            Thread.Sleep(numberOfPeople * 1000);
            return _names.Take(numberOfPeople).ToDictionary(key => key.Key, value => value.Value);
        }
    }
}