Everyone celebrates holidays differently. Some people set up haunted houses for Halloween, catch a football game on Thanksgiving, or watch Die Hard on Christmas. Google decided to celebrate Pi Day the best way it knew how: using Google Cloud to compute the number Pi to a record-breaking 31.4 trillion decimal places.
Google said it calculated Pi to 31,415,926,535,897 decimal places--setting a new Guiness World Record in the process. That's almost 9 trillion digits more than the previous record holder, Peter Trueb, set in November 2016. But the attempt wasn't just record-breaking; it's also unique in several important ways.
This attempt used the y-cruncher Pi benchmark program developed by Alexander J. Yee. On his Numberworld website, Yee said that he confirmed Google's results and also shared a verification file for the computation. Additionally, Yee broke down several of the key differentiators between Google's attempt and previous efforts.
Yee said this is the first Pi record done with a commercial cloud service, SSDs, network storage and the AVX512 instruction set. It's also the second record attempt using y-cruncher "that has encountered and recovered from a silent hardware error." But the most interesting takeaways come down to storage limitations.
"The computation racked up a total of 10PB of reads and 9PB of writes," Yee said. "9PB of writes is enough to destroy the average consumer SSD 10 times over." He added that "the speed of this computation was 8-to-1 bottlenecked by the storage bandwidth," which is "the worst it has ever been in the current era."
Yee also broke down the CPU utilization of every record-setting attempt in this table:
| Date | Digits | Who | CPU Utilization |
|---|---|---|---|
| January 2019 | 31.4 trillion | Emma Haruka Iwao | 12 percent |
| November 2016 | 22.4 trillion | Peter Trueb | 22 percent |
| October 2014 | 13.3 trillion | Sandon Van Ness "houkouonchi" | 36 percent |
| December 2013 | 12.1 trillion | Shigeru Kondo | 37 percent |
| October 2011 | 10 trillion | Shigeru Kondo | ~77 percent |
| August 2010 | 5 trillion | Shigeru Kondo | 35.89 percent |
Of course, this has to do with computations resulting in 31.4 trillion digits. Most people aren't going to expect their SSDs to keep up with tasks like that. (Just like most folks probably aren't going to get all that excited about Pi or its holiday.) But this still offers a peek at how tasks like this are limited.
Google won't end its Pi celebrations end on Pi Day. The company's also introduced the aptly named Pi Day Celebration cloud experiment to its Showcase experiments site to let you "generate a custom art piece from digits of π that you pick." It's also hosting a technical session with Yee at Google Cloud Next 19, which is in San Francisco from April 9-11.
