C# program runs slowly on multiple instances

Question

Now a days I'm practicing some programs of C#. I have an issue in this program.

I have created this program and it took 21 seconds to execute and my CPU usage is 20% and Ram usage is 1Gb max.

 

static void Main(string[] args)
        {
            string str = Console.ReadLine();

            if (str == "start")
            {
               // FrameRecord(40, 140, 780, 570, 2000, "E:\\imgCH1\\", 1);

                Stopwatch sw = new Stopwatch();
                for (int i = 1; i < 200000; i++)
                {
                    sw.Start();

                    Console.WriteLine("Acccessed Value" + i.ToString());
                    Console.WriteLine("Time " + sw.ElapsedMilliseconds);

                }


            }


            Console.Read();
        }

but when I create 2 instances of this It took 140 seconds and CPU usage is 20 % and Ram usage is 1GB max.

Can you please help me, how can I run multiple instances which will take 21 seconds but can utilize my Ram and CPU as maximum.