using System;

using System.Diagnostics;

using System.Linq;

using System.Threading.Tasks;

​

public class Program

{

    public static void Main(string[] args)

    {

        var count = 10000;

        Console.WriteLine("GetData without unnecessary async/await: {0} ms", DoTest(count, () =>

        {

            var temp = GetData1();

        }).ToString());

        Console.WriteLine("GetData with unnecessary async/await: {0} ms", DoTest(count, () =>

        {

            var temp = GetData2();

        }).ToString());

    }

​

    static Task<int[]> GetData()

    {

        return Task.Run<int[]>(() => Enumerable.Range(0, 100).ToArray());

    }

​

    static Task<int[]> GetData1()

    {

        return GetData();

    }

​

    static async Task<int[]> GetData2()

    {

        return await GetData();

    }

​

    static long DoTest(int count, Action action)

    {

        var sw = Stopwatch.StartNew();

        for (int i = 0; i < count; ++i)

        {

            action();

        }

​

        return sw.ElapsedMilliseconds;

    }

}

​