Simple performance comparison between C# Dictionary and if / switch statements

DictionaryTest.cs

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

namespace DictionaryTest
{
    class Program
    {
        /* CPU: AMD Ryzen Threadripper 1950x @ 4.0 Ghz
         * Count: 100000000
         * GetWeekDayNumberUsingIf,         400000000, 00:00:00.4316731
         * GetWeekDayNumberUsingSwitch,     400000000, 00:00:00.4087778
         * GetWeekDayNumberUsingDictionary, 400000000, 00:00:00.8983910 
        */
        
        /* https://dotnetfiddle.net/
         * Count: 100000000
         * GetWeekDayNumberUsingIf,         400000000, 00:00:01.9071346
         * GetWeekDayNumberUsingSwitch,     400000000, 00:00:00.9301885
         * GetWeekDayNumberUsingDictionary, 400000000, 00:00:02.7281431
        */

        public static void Main(string[] args)
        {
            int count = 100000000;
            var methodsToTest = new List<KeyValuePair<string, Func<DayOfWeek, int>>>()
            {
                new KeyValuePair<string, Func<DayOfWeek, int>>(nameof(GetWeekDayNumberUsingIf), GetWeekDayNumberUsingIf),
                new KeyValuePair<string, Func<DayOfWeek, int>>(nameof(GetWeekDayNumberUsingSwitch), GetWeekDayNumberUsingSwitch),
                new KeyValuePair<string, Func<DayOfWeek, int>>(nameof(GetWeekDayNumberUsingDictionary), GetWeekDayNumberUsingDictionary)
            };

            foreach (var method in methodsToTest)
            {
                int sum = 0;
                Stopwatch stopwatch = new Stopwatch();

                stopwatch.Start();
                for (int i = 0; i < count; i++)
                {
                    DayOfWeek day = (DayOfWeek)(i % 7);
                    sum += method.Value(day);
                }
                stopwatch.Stop();
                Console.WriteLine($"{method.Key}, {sum}, {stopwatch.Elapsed}");
            }
        }

        static Dictionary<DayOfWeek, int> DayOfWeekNumbers = new Dictionary<DayOfWeek, int>()
        {
            { DayOfWeek.Monday, 1 },
            { DayOfWeek.Tuesday, 2 },
            { DayOfWeek.Wednesday, 3 },
            { DayOfWeek.Thursday, 4 },
            { DayOfWeek.Friday, 5},
            { DayOfWeek.Saturday, 6 },
            { DayOfWeek.Sunday, 7 }
        };

        public static int GetWeekDayNumberUsingIf(DayOfWeek day)
        {
            if (day == DayOfWeek.Monday)
            {
                return 1;
            }
            else if (day == DayOfWeek.Tuesday)
            {
                return 2;
            }
            else if (day == DayOfWeek.Wednesday)
            {
                return 3;
            }
            else if (day == DayOfWeek.Thursday)
            {
                return 4;
            }
            else if (day == DayOfWeek.Friday)
            {
                return 5;
            }
            else if (day == DayOfWeek.Saturday)
            {
                return 6;
            }
            else if (day == DayOfWeek.Sunday)
            {
                return 7;
            }

            throw new ArgumentException();
        }

        public static int GetWeekDayNumberUsingSwitch(DayOfWeek day)
        {
            switch (day)
            {
                case DayOfWeek.Monday: return 1;
                case DayOfWeek.Tuesday: return 2;
                case DayOfWeek.Wednesday: return 3;
                case DayOfWeek.Thursday: return 4;
                case DayOfWeek.Friday: return 5;
                case DayOfWeek.Saturday: return 6;
                case DayOfWeek.Sunday: return 7;
                default: throw new ArgumentException();
            }
        }

        public static int GetWeekDayNumberUsingDictionary(DayOfWeek day)
        {
            if (DayOfWeekNumbers.TryGetValue(day, out int value))
            {
                return value;
            }

            throw new ArgumentException();
        }
    }
}