List<T> constructor differences

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using BenchmarkDotNet.Attributes;

namespace ConsoleApplication2
{
    public class ListPerformance
    {
        const int size = 100000;

        [Benchmark]
        public void DefaultConstructorUsed()
        {
            var list = new List<int>();
            for (int i = 0; i < size; i++)
            {
                list.Add(i);
            }
        }

        [Benchmark]
        public void ConstructorWithSizeUsed()
        {
            var list = new List<int>(size);
            for (int i = 0; i < size; i++)
            {
                list.Add(i);
            }
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            BenchmarkDotNet.Running.BenchmarkRunner.Run<ListPerformance>();
        }
    }
}