methods

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Diagnostics;

namespace testspeed {
    class Program {
        static int mAxInt = int.MaxValue / 1000;

        static void Main(string[] args) {
            int[] speedArray = new int[mAxInt];

            for (int i = 0; i < mAxInt; i++)
                speedArray[i] = i;

            int[] arrSpeed2 = new int[mAxInt];
            Array.Copy(speedArray, arrSpeed2, mAxInt);
            int[] arrSpeed3 = new int[mAxInt];
            Array.Copy(speedArray, arrSpeed3, mAxInt);

            List<int> speedList = speedArray.ToList();

            Stopwatch s = new Stopwatch();

            s.Start();
            for(int i = 0; i < 10; i++) {
                moveElement(ref speedArray, 500000);
            }
            s.Stop();
            Console.WriteLine("Speed for moveElement: " + s.ElapsedMilliseconds + ", ticks: " + s.ElapsedTicks);

            s.Reset();
            s.Start();
            for(int i = 0; i < 10; i++) {
                ShiftRightAt<int>(arrSpeed2, 500000);
            }
            s.Stop();
            Console.WriteLine("Speed for ShiftRightAt: " + s.ElapsedMilliseconds + ", ticks: " + s.ElapsedTicks);

            s.Reset();
            s.Start();
            for (int i = 0; i < 10; i++) {
                shiftthing(ref speedList, 500000);
            }
            s.Stop();
            Console.WriteLine("Speed for shiftlist: " + s.ElapsedMilliseconds + ", ticks: " + s.ElapsedTicks);

            s.Reset();
            s.Start();
            for (int i = 0; i < 10; i++) {
                arrayCopy(500000, ref arrSpeed3);
            }
            s.Stop();
            Console.WriteLine("Speed for arrayCopy: " + s.ElapsedMilliseconds + ", ticks: " + s.ElapsedTicks);

            Console.ReadLine();
        }

        public static void moveElement(ref int[] array, int index) {
            int[] save = new int[] { array[index] };
            var rest = array.Take(index).Concat(array.Skip(index + 1));
            array = save.Concat(rest).ToArray();
        }

        public static void ShiftRightAt<T>(T[] array, int index) {
            if (index < 0 || index >= array.Length) return; // throw exception

            var element = array[index]; // take out the element

            for (int i = index; i > 0; i--) {
                array[i] = array[i - 1];
            }

            array[0] = element;
        }

        public static void shiftthing(ref List<int> list, int index) {
            var mem = list[index];
            list.Remove(index);
            list.Insert(0, mem);
        }

        public static void arrayCopy(int elementAt, ref int[] array) {
            int[] arr1 = new int[array.Length];
            arr1[0] = array[elementAt];
            Array.Copy(array, 0, arr1, 1, elementAt);
            Array.Copy(array, elementAt + 1, arr1, elementAt + 1, array.Length - elementAt - 1);
        }
    }
}