using System;

using System.Collections.Generic;

using System.Threading.Tasks;

using System.Diagnostics;

using System.Net.Http;

public class Program

{

    public async static Task Main()

    {

        Console.WriteLine("start");

        var httpClient = new HttpClient();

​

        Stopwatch timer = new Stopwatch();

        timer.Start();

        await httpClient.GetAsync("https://www.tut.by");

        await httpClient.GetAsync("https://www.tut.by");

        await httpClient.GetAsync("https://www.tut.by");

        timer.Stop();

        Console.WriteLine(timer.Elapsed);

        timer.Restart();

        var t1 = httpClient.GetAsync("https://www.tut.by");

        var t2 = httpClient.GetAsync("https://www.tut.by");

        var t3 = httpClient.GetAsync("https://www.tut.by");

        await t1; await t2; await t3;

        Console.WriteLine(timer.Elapsed);

​

        Console.WriteLine("end");

    }

}

​