using System;

using System.Diagnostics;

using System.Collections.Generic;

using System.Linq;

​

public class Program

{

    public static void Main()

    {

        var testList = new List<TestData>();

        for (int i = 0; i < 5000; i++)

            {

                testList.Add(new TestData{

                Prop1 = "something" + i,

                    Prop2 = "another" + i,

                    Prop3 = "please" + i,

                    Prop4 = "help" + i,

                    Prop5 = "fast" + i,

                    Prop6 = i

                });

            }

        Stopwatch stopwatch = Stopwatch.StartNew();

        Console.WriteLine(testList.Where(x => x.Prop6 % 2 == 0).Count());

        stopwatch.Stop();

        Console.WriteLine("First Test");

        Console.WriteLine(stopwatch.GetTimeString());

        stopwatch = Stopwatch.StartNew();

        Console.WriteLine(testList.Count(x => x.Prop6 % 2 == 0));

        stopwatch.Stop();

        Console.WriteLine("Second Test");

        Console.WriteLine(stopwatch.GetTimeString());

    }

}

​

public static class StopwatchExt

{

    public static string GetTimeString(this Stopwatch stopwatch, int numberofDigits = 1)

    {

        double time = stopwatch.ElapsedTicks / (double)Stopwatch.Frequency;

        if (time > 1)

            return Math.Round(time, numberofDigits) + " s";

        if (time > 1e-3)

            return Math.Round(1e3 * time, numberofDigits) + " ms";

        if (time > 1e-6)

            return Math.Round(1e6 * time, numberofDigits) + " µs";

        if (time > 1e-9)

            return Math.Round(1e9 * time, numberofDigits) + " ns";

        return stopwatch.ElapsedTicks + " ticks";

    }

}

​

public class TestData { 

    public string Prop1 { get; set; }

    public string Prop2 { get; set; }

    public string Prop3 { get; set; }

    public string Prop4 { get; set; }

    public string Prop5 { get; set; }

    public int Prop6 { get; set; }

}