Said mine was an old machine :-{
Without getting the calculator out it looks as if your tests ran about 50% faster then mine - with the odd exception of the VFP string test which was about twice as fast ?

>On my computer:
>Jose's code completes in 0.868 seconds and in 0.441 seconds respectively.
>C# code (below) completes in 0.29 seconds and 0.016 seconds respectively.
>
>

>
>using System;
>using System.Text;
>
>namespace SpeedTest
>{
>    using System.Diagnostics;
>
>    public class Program
>    {
>        public static void Main()
>        {
>            SpeedTest();
>
>            Console.Write("\n\nAny key...");
>            Console.ReadKey();
>        }
>
>        private static void SpeedTest()
>        {
>            const int MaxIndex = 1000000;
>
>            var stopwatch = new Stopwatch();
>            stopwatch.Start();
>
>            for (var index = 0; index < MaxIndex; index++)
>            {
>                var var1 = Math.Log(index) + 
>                    Math.Cos(index) + 
>                    Math.Sin(index) + 
>                    Math.Log(index) + 
>                    Math.Exp(index);
>            }
>
>            stopwatch.Stop();
>            Console.WriteLine("Test 01: {0}", stopwatch.Elapsed);
>
>            // AM  using string type in .NET for this type of test
>            // would be unreasonable. StringBuilder Class is used instead.
>            var stringBuilder = new StringBuilder();
>
>            stopwatch.Reset();
>            stopwatch.Start();
>
>            for (var index = 0; index < MaxIndex; index++)
>            {
>                stringBuilder.Append("xx");
>            }
>
>            string result = stringBuilder.ToString();
>
>            stopwatch.Stop();
>            Console.WriteLine("Test 02: {0}", stopwatch.Elapsed);
>        }
>    }
>}
>