Program.cs

using BenchmarkDotNet.Running;
using BenchmarkDotNet.Attributes;

namespace Benchmark
{
    public static class Program
    {
        public static void Main()
        {
            BenchmarkRunner.Run<RefProperty>();
        }
    }

    public class RefProperty
    {
        private const int n = 1000000;

        [Benchmark]
        public static void Modern()
        {
            var person = new ModernPerson();
            for (int i = 0; i < n; i++)
            {
                person.Age++;
            }
        }

        [Benchmark]
        public static void OldSchool()
        {
            var person = new OldSchoolPerson();
            for (int i = 0; i < n; i++)
            {
                person.Age++;
            }
        }
    }

    public class OldSchoolPerson
    {
        public string Name { get; set; }
        public int Age { get; set; }
    }

    public class ModernPerson
    {
        private string _name;
        private int _age;

        public ref string Name => ref _name;
        public ref int Age => ref _age;
    }

}