![scientists calculate pi trillion scientists calculate pi trillion](https://fivethirtyeight.com/wp-content/uploads/2018/03/roeder-piday-diagram.png)
The winning configuration? “We designed a cluster of one computational node and 32 storage nodes, for a total of 64 iSCSI block storage targets.”
“In other words, the calculation could’ve taken 300 days instead of 157 days!” “Overall, the final design for this calculation was about twice as fast as our first design,” Iwao’s blog post notes. “To store the final results, we attached two 50TB disks directly to the compute node.”Īnd before they even began, the team also used the Terraform tool (along with a home-grown program) to performance-test dozens of different possible infrastructure options - and different parameters for the pi-calculating program y-cruncher. “We needed a robust, durable storage system that could handle petabytes of data without any loss or corruption, while fully utilizing the 100 Gbps bandwidth. “Because the dataset doesn’t fit into main memory, the speed of the storage system was the bottleneck of the calculation,” Iwao wrote. (Versus just 19TB in 2019 - or just 606 years of high-definition movies.) It took 515TB just to store the final number.Ī screenshot from our interview with Google Cloud advocate Emma Haruka Iwao – June 7 2022īut it turns out that calculating 100 trillion digits of pi isn’t just a storage problem. Iwao also writes that just the amount of data processed - 82,000TB - is equivalent to 2,598 years of high-definition movies. But in order to calculate pi, you need to keep and store a lot of these different numbers, a few variables in the equation. “So pi is just one number, that’s 100 trillion digits. “The algorithm has multiple variables,” Iwao explained in an interview with The New Stack on Tuesday. Yes, that’s 82PB of output - a number that’s even more massively large than the 515TB used to ultimately store the number. “Back in 2019 when we did our 31.4-trillion digit calculation, egress throughput was only 16 Gbps,” Iwao points out in a second more-technical blog post, “meaning that bandwidth has increased by 600% in just three years… This increase was a big factor that made this 100-trillion experiment possible, allowing us to move 82.0PB of data for the calculation, up from 19.1PB in 2019.” This meant that their main compute node - running Debian Linux 11 - ended up with a jaw-dropping 100Gbps egress bandwidth support (which is critical for a project like this, which uses a network-based, shared storage architecture). Back in 2019, using Google Compute Engine (powered by Google Cloud), Iwao had fired up 25 virtual machines which churned non-stop for 121 days, ultimately calculating pi out to a record 31,415,926,535,897 places - the first time a record-setting calculation had been performed using the cloud.īut this time, to calculate pi all the way out to its 100,000,000,000,000th decimal place, Iwao worked with a team of three more developer advocates - a team which availed themselves of the very latest infrastructure.įor starter, Iwao’s team switched to Google’s new Virtual NIC (gVNIC) network driver, which tightly integrates with Google’s Andromeda virtual network stack, giving them the benefit of a higher throughput with a lower latency. Iwao had already set an earlier record for digits of pi calculated. “One of those things, you guessed it, is using a program to calculate digits of pi.” “As a developer advocate at Google Cloud, part of my job is to create demos and run experiments that show the cool things developers can do with our platform,” Iwao explained in the blog post. Iwao and her team had put 128 virtual CPUs on the calculations - and a whopping 894GB of RAM. “We’d calculated the most digits of π ever - 100 trillion to be exact.”īut what’s equally interesting is how they did it. “I was going to be the first and only person to ever see the number,” Iwao remembered in a blog post published this week. After running calculations for 157 days, 23 hours, 31 minutes and 7.651 seconds, their big moment arrived when it was time to check. “The 100-trillionth decimal place of π (pi) is 0.”Įmma Haruka Iwao knows - because she led the first team that ever calculated every single digit.