There is a program called Super Pi that calculates and outputs pi to a ridiculously large ammount of digits. 32 millionth digit being the most. It is used to test a computers procession power.
http://files1.extremeoverclocking.com/11c6e25451a7cf2585612482793b1a0f/benchmarks/super_pi.zip
You can even check out what pi to the 32 million looks like by running the program and checking out pi_data.txt.
Here is the challenge! Download the program and unzip it. Open Super Pi and click "Calculate". Select 4 million and hit start. It will run through 21 (or so) loops and give you a time for the calculation. Post your best time! Also say what processor you have.
Pentium D 830: 3 minutes 48 seconds