using System;
using System.Diagnostics;

namespace Test
{
    class Program
    {
        static void Main(string[] args)
        {
            Stopwatch sw = new Stopwatch();
            int[] data = new int[100000];

            sw.Start();
            Array.Clear(data, 0, data.Length);
            sw.Stop();
            Console.WriteLine("Array.Clear - " + sw.ElapsedTicks);

            sw.Reset();
            sw.Start();
            data = new int[100000];
            sw.Stop();
            Console.WriteLine("new int[] - " + sw.ElapsedTicks);

            sw.Reset();
            sw.Start();
            for (int i = 0; i < data.Length; i++) data[i] = 0;
            sw.Stop();
            Console.WriteLine("for - " + sw.ElapsedTicks);
        }
    }
}

using System;
using System.Diagnostics;

namespace Test
{
    public class Program
    {
        private static int[] globalData;

        private static void Main()
        {
            const int cycles = 100;
            const int arraySize = 256 * 256;

            long clearTicks = 0;
            long allocTicks = 0;

            var sw = new Stopwatch();

            globalData = new int[arraySize];
            for (var i = 0; i < cycles; i++)
            {
                sw.Reset();
                sw.Start();

                Array.Clear(globalData, 0, globalData.Length);

                sw.Stop();

                clearTicks += sw.ElapsedTicks;
            }

            for (var i = 0; i < cycles; i++)
            {
                sw.Reset();
                sw.Start();

                globalData = new int[arraySize];

                sw.Stop();

                allocTicks += sw.ElapsedTicks;
            }

            Console.WriteLine("CLEAR TICKS: " + clearTicks + " ALLOC TICKS: " + allocTicks);

            Console.ReadKey();
        }
    }
}