Bench test your PC!

Well, I was bored, so I made a C# app to calculate prime numbers.

.net 2.0 framework required.

Open it, enter:

1000000 (one million)

And wait for it to complete.

Then post the time it shows.

Tips: Close all background applications.

Note that it will get slower as the numbers get bigger.

And if it's taking up CPU, you should expect it!

Download:
http://www.mediafire.com/download.php?1itj42pyohw

..source:

 Spoiler

Code:

using System;
using System.Diagnostics;


namespace StaticExtensionMethod
{


    class Test
    {

        static Stopwatch primes(int cap)
        {
            Stopwatch timer = new Stopwatch();
            timer.Start();
            for (int num = 2; num <= cap; num++)
            {


                int i;
                for (i = 2; i < num; i++)
                {
                    int n = num % i;
                    if (n == 0)
                    {
                        
                        break;
                    }
                }
                if (i == num)
                {
                    Console.WriteLine(num);
                }
            }
            timer.Stop();
            return timer;

        }





        public static void Main()
        {

            int cap = 0;
            int.TryParse(Console.ReadLine(), out cap);
            Console.WriteLine("End user input\r\n-------------\r\n\r\n");
            Stopwatch timeTaken = primes(cap);
            Console.WriteLine("{0}d, {1}h, {2}m, {3}s taken for {4} as cap", timeTaken.Elapsed.Days, timeTaken.Elapsed.Hours, timeTaken.Elapsed.Minutes, timeTaken.Elapsed.Seconds, cap);
            Console.ReadLine();
        }
    }


}

Code:

if (i == num)
                {
                    Console.WriteLine(num);
                }

That makes me cry. Writelines are very CPU intensive. Only the end result is needed.

Code:

Stopwatch timer = new Stopwatch();
            timer.Start();
            int num;
            int i;
            for (num = 3; num <= cap; num += 2)
            {
                for (i = 2; i < num; i++)
                {
                    if (num % i == 0)
                    {    
                        break;
                    }
                }
            }

There are other optimizations you could use, but these are some pretty good ones for the moment. I guess it's also because I was trained in the ANSI standard. >_>

Well it does give us a nice visual representation of the process :3.

My computer is slow. Still going through.

EDIT: Done. 17m 47 seconds.

Okay, I re-ran it. Here;s my result.

0d, 0h, 5m, 13s taken for 1000000 as cap

Using the optimized test or the original?

Your computer is much faster than mine either way

Original. The optimized wasn't faster at all.

3m 12s.

3:58. :x
Now let's see who can run the program by hand fastest.

10:52

9m 47s. D:

Lol, I actually had a TI-Basic (graphing calculator language) program that spit out prime numbers on my calculator... it took about an entire class period to get from 2 to 8000-ish, when I aborted it. I didn't bother to implement a stopping point, so it would've gone on forever until it ran out of battery.

5:25. What do you know, that's my birthday.

3:09 - without closing anything
2:51 - closed firefox, media player and a buncha other windows

lol 18 seconds difference.

13:xx -_- I'm going to fully reïnstall windows soon, because my computer has been slow for the last 2 weeks, even though I clean it all the time...