The number pi is known to have an infinite number of decimal places that do not even start somewhere, to reiterate - it is irrational and even transcendental. A great research subject so when it comes to practice extremely accurate calculations. to calculate pi to as many decimal places, has indeed to be no practical relevance, but still a long tradition.

were While many world records in Pi Calculate achieved on supercomputers (last 2,577,000,000,000 digits of Daisuke Takashi), the Paris-based software developer Fabrice Bellard has now set up with a standard Core i7 PC a new record: 2,699,999,990,000 decimal places, almost 2.7 trillion. The calculation took a total of 131 days.

First Bellard calculated the binary representation of the number, which lasted 103 days. 13 days processing time included in a plausibility check, which ensures mathematical methods with very high probability that the result is correct. Since the Pi-lovers prefer to consider their digits in the decimal system, a conversion matured, which lasted 12 days. Three more days of computing time finally included in the verification of conversion, so you can go out with a very high probability of a correct result here.

Calculating with such accuracy has its own challenges, after all the numbers by far not fit into the main memory: But the result is 1,137 gigabytes. During the calculation of the algorithm needed the 6.42 times that amount of data, about 7.3 terabytes. So Bellard screwed five plates á 1.5 terabytes in its Core i7 PC and linked it with the Linux distribution Fedora 10 to a RAID 0, so as to achieve a throughput of about 500 MB / s. The 6 GB of main memory of the system are rather modest in comparison.

More details can be found on a web page of the author, in particular, a more detailed description (PDF) to that used Chudnovsky series and the methods to evaluate them ,. The 50 decimal places from the 2.699.999.989.951ten incidentally loud 9256371619 3901058063 3448436720 6294374587 7597230153. Well, that one that now finally know.(Bo)