请各位来帮我看下这段代码，分析一下啊。谢谢了


  //更新红绿灯状态
        public void UpdateLight(object obj)
        {
            try
            {
                Dictionary<string, string> dic_light = obj as Dictionary<string, string>;
                List<Dictionary<string, string>> dic_lights = new List<Dictionary<string, string>>();
                for (int i = 0; i < 4; i++)
                {
                    Dictionary<string, string> dic = new Dictionary<string, string>();
                    foreach (var item in dic_light)
                    {
                        if (Convert.ToInt32(item.Key) > i * 40 && Convert.ToInt32(item.Key) <= (i + 1) * 40)
                        {
                            dic.Add(item.Key, item.Value);
                        }
                    }
                    dic_lights.Add(dic);
                }
                for (int i = 0; i < dic_lights.Count; i++)
                {
                    Thread thread = new Thread(new ParameterizedThreadStart(DealLight));
                    thread.Start(dic_lights[i]);
                }
            }
            catch (Exception ex)
            {
                System.Diagnostics.Debug.WriteLine("--------更新红绿灯异常------" + ex.ToString());
                return;
            }
        }        //更新红绿灯状态
        public void DealLight(object obj)
        {
            Dictionary<string, string> dic_light = obj as Dictionary<string, string>;
            try
            {
                foreach (PictureBox pic in listLightPic)
                {
                    foreach (var item in dic_light)
                    {
                        //pic.Name格式：light_11
                        if (pic.Name.Substring(pic.Name.IndexOf('_') + 1) == item.Key)
                        {
                            this.Invoke(new MyInvokeUpdateLight(SetLightPicImage), pic, item.Value);
                        }
                    }
                }
            }
            catch (Exception ex)
            {
                System.Diagnostics.Debug.WriteLine("--------更新红绿灯异常------" + ex.ToString());
                return;
            }
        }        //给红绿灯设置对应背景图片
        public void SetLightPicImage(PictureBox pic, string value)
        {
            switch (value)
            {
                case "绿色":
                    pic.BackgroundImage = image_lv;
                    break;
                case "红色":
                    pic.BackgroundImage = image_hong;
                    break;
                case "绿闪":
                    pic.BackgroundImage = image_lvshan;
                    break;
                case "红闪":
                    pic.BackgroundImage = image_hongshan;
                    break;
                case "故障":
                    pic.BackgroundImage = image_guzhang;
                    break;
            }
        }我WINFORM程序界面上有有160个picturebox控件，每一个控件对应一个红绿灯。
现在的情况是我在笔记本上这样做，每个picturebox的背景图片基本能达到同时更新。但是我把这程序移植到一个硬件配置比较差的电脑上运行的时候，就出现是每个picturebox依次一个个的更新，不像在笔记本上那样能几乎同时更新。让我困惑的是，我是用几个线程分别去更新的（分四个线程更新，每个线程去更新40个picturebox的背景图片），为什么会出现所有的picturebox依次一个个去更新呢？真是电脑性能问题吗？劳烦大神帮忙看下啊多线程C#  PictureBox