Software for calculating π

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Over the years, several programs have been written for calculating pi (π) to many digits on personal computers.

1 General-purpose
2 Special-purpose
3 Most digits calculated on a home computer
4 See also
5 References
6 External links

[edit] General-purpose

Most computer algebra systems can calculate π and other common mathematical constants to any desired precision.

Functions for calculating π are also included in many general libraries for arbitrary-precision arithmetic, for instance MPFR.

[edit] Special-purpose

Programs designed for the specific purpose of calculating π may have better performance than general-purpose mathematical software. They typically implement checkpointing and efficient disk swapping to facilitate extremely long-running and memory-expensive computations.

PiFast, by Xavier Gourdon was the fastest program for Microsoft Windows in 2003. According to its author, it can compute one million digits in 3.5 seconds on a 2.4 GHz Pentium 4.^[1] PiFast can also compute other irrational numbers like e and √2. It can also work at lesser efficiency with very little memory (down to a few tens of megabytes to compute well over a billion (10⁹) digits). This proprietary freeware tool is a popular benchmark in the overclocking community. PiFast 4.4 is available from Stu's Pi page. PiFast 4.3 is available from Gourdon's page.

QuickPi by Steve Pagliarulo for Windows is faster than PiFast for runs of under 400,000,000 digits. Version 4.5 is available on Stu's Pi Page below. Like PiFast, QuickPi can also compute other irrational numbers like e, √2, and √3. The software may be obtained from the Pi-Hacks Yahoo! forum, or from Stu's Pi page.

[edit] Most digits calculated on a home computer

The most digits calculated on a home PC is by Shigeru Kondo on his Xeon X5460 @3.16Ghz with 48GB RAM using Windows 2003 server x64. Kondo calculated 100,000,000,000 digits using the 64-bit version of Pagliarulo's QuickPi v4.5. It took just under 40 days beginning on January 16, 2008.

Stu's Pi page is compiling a listing of large digit runs (over 1-gig or 1,073,741,824).

Latest record for digits on a supercomputer is 1,241,100,000,000 digits as of November 2002 by Yasumasa Kanada's lab at The University of Tokyo.