并行程序花费太多时间

Question

这是我的代码：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;
using System.Collections.Concurrent;


namespace ConsoleApplication2
{
    public class c_Thread
    {
        public bool ThreadOngoing;
        public c_Thread()
        {
            ThreadOngoing = false;
        }
        public void CallToChildThread1(string key, ref List<int> nums, ref ConcurrentDictionary<string, List<int>> container)
        {
            container.TryAdd(key, nums);
        }

        public void CallToChildThread2(string key, ref List<int> nums, ref Dictionary<string, List<int>> container)
        {
            container.Add(key, nums);
        }
    }

    class Program
    {

        static void Main(string[] args)
        {
            RunProgram();
            Console.ReadKey();
        }
        static void RunProgram()
        {
            System.Diagnostics.Stopwatch sw = System.Diagnostics.Stopwatch.StartNew();
            Console.WriteLine("Normal");
            Program1();
            sw.Stop();
            Console.WriteLine("Time taken: {0}ms", sw.Elapsed.TotalMilliseconds);
            sw.Reset();
            sw.Start();
            Console.WriteLine("Parallel");
            Program2();
            sw.Stop();
            Console.WriteLine("Time taken: {0}ms", sw.Elapsed.TotalMilliseconds);
        }

        static void Program1()
        {

            c_Thread cc = new c_Thread();
            Dictionary<string, List<int>> container1 = new Dictionary<string, List<int>>();
            List<int> aList = new List<int>();
            List<int> bList = new List<int>();
            string printLine;
            aList.Add(2);
            aList.Add(4);
            aList.Add(2);
            aList.Add(2);
            aList.Add(4);
            aList.Add(2);
            aList.Add(2);
            aList.Add(4);
            aList.Add(2);
            aList.Add(2);
            aList.Add(4);
            aList.Add(2);

            bList.Add(1);
            bList.Add(3);
            bList.Add(1);
            bList.Add(1);
            bList.Add(3);
            bList.Add(1);
            bList.Add(1);
            bList.Add(3);
            bList.Add(1);
            bList.Add(1);
            bList.Add(3);
            bList.Add(1);
            cc.CallToChildThread2("param1", ref aList, ref container1);
            cc.CallToChildThread2("param2", ref bList, ref container1);
            foreach (string key in container1.Keys)
            {
                printLine = key + ": ";
                foreach (int val in container1[key])
                    printLine += val + " ";
                Console.WriteLine(printLine);

            }
        }

        static void Program2()
        {
            c_Thread cc = new c_Thread();
            ConcurrentDictionary<string, List<int>> container1 = new ConcurrentDictionary<string, List<int>>();
            List<int> aList = new List<int>();
            List<int> bList = new List<int>();
            string printLine;
            aList.Add(2);
            aList.Add(4);
            aList.Add(2);
            aList.Add(2);
            aList.Add(4);
            aList.Add(2);
            aList.Add(2);
            aList.Add(4);
            aList.Add(2);
            aList.Add(2);
            aList.Add(4);
            aList.Add(2);

            bList.Add(1);
            bList.Add(3);
            bList.Add(1);
            bList.Add(1);
            bList.Add(3);
            bList.Add(1);
            bList.Add(1);
            bList.Add(3);
            bList.Add(1);
            bList.Add(1);
            bList.Add(3);
            bList.Add(1);
            Thread myNewThread1 = new Thread(() => cc.CallToChildThread1("param1", ref aList, ref container1));
            myNewThread1.Start();
            Thread myNewThread2 = new Thread(() => cc.CallToChildThread1("param2", ref bList, ref container1));
            myNewThread2.Start();
            myNewThread1.Join();
            myNewThread2.Join();
            foreach (string key in container1.Keys)
            {
                printLine = key + ": ";
                foreach (int val in container1[key])
                    printLine += val + " ";
                Console.WriteLine(printLine);

            }
        }
    }
}

两种方法Program1()和Program2()做同样的事情。 Program1()调用CallToChildThread2()将密钥值对输入到字典中，但是Program2()调用CallToChildThread1()将密钥值对并行输入并发字典。

输出如下：