Duo Calculates Pi to 5 Trillion Places

August 13, 2010 

 Systems engineer Shigeru Kondo (Nagoya University) and Alexander J. Yee, a U.S. computer science student at Northwestern University, claim to have calculated the value of pi to five trillion digits.

If their work stands up, they will have shattered the pi calculation record set earlier the year by Fabrice Bellard, who calculated the value of pi to 2.7 trillion digits.

Kondo and Yee’s computations took place on a single desktop computer that required roughly 22 terabytes of disk space and 96 gigabytes of RAM. The main computation took 90 days, followed by five days of verification on two desktop computers.

Yee noted that unlike Bellard’s record, which focused on efficiency and getting the most out of a small amount of hardware, the duo's computation "focused more on getting the most performance and scalability from a lot of hardware."

"The main challenge for a computation of such a size," Yee said, "is that both software and hardware are pushed beyond their limits. For such a long computation and with so much hardware, failure is not just a probability. It is a given. There are simply too many components that can fail," he continued.

Therefore, the critical issues they resolved were determining how much the hardware could be expanded while maintaining an acceptable level of reliability and whether it is possible to build enough fault-tolerance into the software to cover for hardware failure."

The five trillionth digit, by the way, turns out to be a 2.

For information on the previous record, see Math in the News article "Pi Calculated to 2.7 Trillion Digits" (January 19, 2010)

Source: Geek System (August 6, 2010)