Lots a V3

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;
using System.Diagnostics;

//  This is due to a wierd unity3d forum question + late night.
//  I write in 71s
//  And read in 64.59s
//  On a Samsung 1TB F3 while doing basic background tasks.

namespace WriteLotsOfV3
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("[R]ead or [W]rite?");

            char selection = Console.ReadLine().ToLower()[0];

            if (selection == 'w')
            {
                Console.WriteLine();
                Console.WriteLine("Writing");
                Console.WriteLine();

                Int32 iterations = 67108864;

                var sw = Stopwatch.StartNew();

                var fs = new FileStream("Vector3s.dat", FileMode.Create);
                var bw = new BinaryWriter(fs);

                var rnd = new Random();

                bw.Write(iterations);

                for (int i = 0; i < iterations; i++)
                {
                    for (int x = 0; x < 3; x++)
                        bw.Write(NextFloat(rnd));
                }
                fs.Flush(true);

                sw.Stop();

                Console.WriteLine(fs.Name);

                Console.WriteLine();

                Console.WriteLine("Finished writing in {0}ms", sw.ElapsedMilliseconds);


                fs.Dispose();
                bw.Dispose();
            }
            else if (selection == 'r')
            {
                Console.WriteLine();
                Console.WriteLine("Reading");
                Console.WriteLine();

                var fs1 = new FileStream("Vector3s.dat", FileMode.Open);
                var br = new BinaryReader(fs1);

                var sw = Stopwatch.StartNew();
                int iterations = br.ReadInt32();

                var data = new float[iterations, 3];

                for (int i = 0; i < iterations; i++)
                {
                    for (int x = 0; x < 3; x++)
                        data[i, x] = br.ReadSingle();
                }

                sw.Stop();

                Console.WriteLine("Finished reading in {0}ms", sw.ElapsedMilliseconds);
                Console.ReadLine();
            }
            else { Console.WriteLine("Invalid"); Console.WriteLine("");  Main(null); }
        }

        //http://stackoverflow.com/questions/3365337/best-way-to-generate-a-random-float-in-c-sharp
        static float NextFloat(Random random)
        {
            double mantissa = (random.NextDouble() * 2.0) - 1.0;
            double exponent = Math.Pow(2.0, random.Next(-126, 128));
            return (float)(mantissa * exponent);
        }
    }


}