LinqPerformance.cs

using System;
using System.Diagnostics;
using System.Linq;

namespace LinqPerformance
{
	class Program
	{
		static void Main(string[] args)
		{
			Random rand = new Random();

			int[] randomData = new int[10000000];
			for (int i = 0; i < randomData.Length; ++i)
			{
				randomData[i] = rand.Next();
			}

			Stopwatch swFor = new Stopwatch();
			swFor.Start();
			int maxFor = MaxFor(randomData);
			swFor.Stop();

			Stopwatch swForeach = new Stopwatch();
			swForeach.Start();
			int maxForeach = MaxForeach(randomData);
			swForeach.Stop();

			Stopwatch swLinq = new Stopwatch();
			swLinq.Start();
			int maxLinq = MaxLinq(randomData);
			swLinq.Stop();

			Console.WriteLine("For loop     {0:0.000}ms", 1000.0 * swFor.ElapsedTicks     / Stopwatch.Frequency);
			Console.WriteLine("Foreach loop {0:0.000}ms", 1000.0 * swForeach.ElapsedTicks / Stopwatch.Frequency);
			Console.WriteLine("LINQ         {0:0.000}ms", 1000.0 * swLinq.ElapsedTicks    / Stopwatch.Frequency);
			Console.ReadLine();
		}

		static int MaxFor(int[] randomData)
		{
			int max = int.MinValue;
			for (int i = 0; i < randomData.Length; ++i)
			{
				if (randomData[i] > max)
				{
					max = randomData[i];
				}
			}
			return max;
		}

		static int MaxForeach(int[] randomData)
		{
			int max = int.MinValue;
			foreach (var val in randomData)
			{
				if (val > max)
				{
					max = val;
				}
			}
			return max;
		}

		static int MaxLinq(int[] randomData)
		{
			return randomData.Max();
		}
	}
}