Generic vs not-generic performance in C#

Question

I\'ve written two equivalent methods:

static bool F(T a, T b) where T : class
{
    return a == b;
}

static bool F2(A a, A b)
{
    return a == b;
         


        

Answer 1

It seems more fair, no?:D

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;

namespace ConsoleApplication58
{
    internal class Program
    {
        private class A
        {

        }

        private static bool F(T a, T b) where T : class
        {
            return a == b;
        }

        private static bool F2(A a, A b)
        {
            return a == b;
        }

        private static void Main()
        {
            const int rounds = 100, n = 10000000;
            var a = new A();
            var fList = new List();
            var f2List = new List();
            for (int i = 0; i < rounds; i++)
            {
                //test generic
                GCClear();
                bool res;
                var sw = new Stopwatch();
                sw.Start();
                for (int j = 0; j < n; j++)
                {
                    res = F(a, a);
                }
                sw.Stop();
                fList.Add(sw.Elapsed);

                //test not-generic
                GCClear();
                bool res2;
                var sw2 = new Stopwatch();
                sw2.Start();
                for (int j = 0; j < n; j++)
                {
                    res2 = F2(a, a);
                }
                sw2.Stop();
                f2List.Add(sw2.Elapsed);
            }
            double f1AverageTicks = fList.Average(ts => ts.Ticks);
            Console.WriteLine("Elapsed for F = {0} \t ticks = {1}", fList.Average(ts => ts.TotalMilliseconds),
                              f1AverageTicks);
            double f2AverageTicks = f2List.Average(ts => ts.Ticks);
            Console.WriteLine("Elapsed for F2 = {0} \t ticks = {1}", f2List.Average(ts => ts.TotalMilliseconds),
                  f2AverageTicks);
            Console.WriteLine("Not-generic method is {0} times faster, or on {1}%", f1AverageTicks/f2AverageTicks,
                              (f1AverageTicks/f2AverageTicks - 1)*100);
            Console.ReadKey();
        }

        private static void GCClear()
        {
            GC.Collect();
            GC.WaitForPendingFinalizers();
            GC.Collect();
        }
    }
}

On my laptop i7-3615qm, generic is faster than not-generic.

See http://ideone.com/Y1GIJK.