Calculating Pi to 10 Trillion Digits; the last number is 5

In August, 2010, [Alexander Yee] and [Shigeru Kondo] won a respectable amount of praise for calculating pi to more digits than anyone else. They’re back again, this time doubling the number of digits to 10 Trillion.

The previous calculation of 5 Trillion digits of Pi took 90 days to calculate on a beast of a workstation. The calculations were performed on 2x Xeon processors running at 3.33 GHz, 96 Gigabytes of RAM, and 32 Terabytes worth of hard drives. The 10 Trillion digit attempt used the same hardware, but needed 48 Terabytes of disk to store everything.

Unfortunately, the time needed to calculate 10 Trillion digits didn’t scale linearly. [Alex] and [Shigeru] waited three hundred and seventy-one days for the computer to finish the calculations. The guys used y-cruncher, a multithreaded pi benchmarking tool written by [Alex]. y-cruncher calculates hexadecimal digits of pi; conveniently, it’s fairly easy to find the nth hex digit of pi for verification.

If  you’re wondering if it would be faster to calculate pi on a top 500 supercomputer, you’d be right. Those boxes are a little busy predicting climate change, nuclear weapons yields, and curing cancer, though. Doing something nobody else has ever done is still an admirable goal, especially if it means building an awesome computer.


  1. tom says:

    What kind of calculations do you think they need that much precision for? :)

  2. It’s the last digit, not number. The number is the whole thing. Sorry, am narrowminded today..

  3. iant says:

    On their website I spotted this

    Pi – Computation
    371 days
    Start : 10:34 AM (JST) October 10, 2010
    Finish: 3:14 PM (JST) October 16, 2011

    Kinda lucky end time coincidence… ;-)

  4. steve eh says:

    MAN….you ruined the ending i was going to do that tomorrow… DANG IT

  5. hazardous says:

    I wish I had 96 gigabytes of ram…. I could run my entire laptop off that much ram….

  6. JoshN says:

    If you read the page it says they lost 180 days due to hardware failure. So it really only took 191 days of computation. That’s nearly linear time.

  7. SpongeBob says:

    How can this number be so long? Is it infinite?
    In a parallel universe, could Pi be a finite number?
    Is God gonna be mad if we find all the decimal of Pi?

  8. William says:

    Now how long would it take on several GPUs?

  9. Mark A says:

    You forgot to say what the value of pi is on this page.
    So here are the first 32 digits.

    Can you please post the first 32 thousand digits.

    • Mark A says:

      Found a few more digits of pi:



      This comment has been modified because: Not accurate after 100 decimal places. Be more careful next time -Brian

  10. Dave The Fixer says:

    What is the point?

  11. GTMoogle says:

    Hmm. Well, I’d heard long ago that you could could create a circle around the visible universe with an error of less than the width of a proton with only X digits of pi, but when I googled, it, I found X = 32, 39, 41, 43, 47, and 50. Well, a bit less than 10 trillion anyway. :}

  12. Laura Harris says:

    Some people keep trying to see if there’s a point where pi stops being irrational. :)

  13. keystoneclimber says:

    Come on, everybody know that supercomputers can’t cure cancer. Only pink ribbons can.

  14. t&p says:

    I got pi by doing something like 1\log2 or something… wish I could remember what I did.

    • Dario says:

      i remember deducing it as the limit of some equation of the radio of a polygon with the number of faces going to +inf.
      it was just a matter of putting like 10000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 faces and you get a lot of accuracy in the result

  15. NatureTM says:

    Only 7.3 trillion more digits until it repeats, keep going!

  16. biozz says:

    any one else think this could have been SOOOO much faster with a set of nvidia teslas? XD

  17. ve3zxq says:

    Oh Goody! i can finally calibrate my new modified Q-32 Space Modulator…and when i’m ready to use it, it will make a great big KABOOM!

  18. Cyril says:

    I know all the digits of Pi.

    Unfortunately, not in order.

  19. MikeK says:

    Rainman would have been proud.

  20. password says:

    errr uhm , pi is wrong :P

    yep it was a pointless self gratification exercise

  21. Leithoa says:

    Knowing more digits of an irrational or a larger prime number A) give you bragging rights B) let you encode/crack more difficult encryption schemes.

  22. William Stevenson says:

    I remember reading an awesome article on the Chudnovsky brothers (think the newyorker linked on wikipedia), it sounded as if their whole house was given over to a supercomputer, it also outlined their various hardships. It would be nice to see an update.

  23. Ben says:

    I actually have access to a top 500 computer for supersonic flow analysis, I might be tempted to give this a go. I’m not sure if I should say exactly what computer but I will say it’s got over 1500 xeon 5660 processors and near 20 TB of ram

  24. I have followed Alexander Yee’s work for awhile, and there are some very good reasons that GPUs are not ideal for calculating pi. I think the main reason is memory bandwidth–when you’re multiplying very long numbers, you’re constantly having to go to RAM, and this is far from speedy with current GPUs. Clustering has similar issues, but the main issue with clusters I think is effective multithreading. Alex discusses that too at his website.

  25. Zackery Fix says:

    The reason for calculation the end of the PI is simple. It is required in order to ‘calculate’ an accurate simulation of our beloved reality.


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