Linus Tech Tips has just set the world record for calculating the most digits of pi, at 300,000,000,000,000 (three hundred trillion), breaking the former record of 202 trillion set in 2024.
Here’s the video they made about it if you’re interested.
Says they used a cluster with 2.2PB of flash drives (that was Kioxia’s contribution) and the calculation took 7.5 months. Article is otherwise sort of useless. I’d like to know more technical and mathematical details. It gives the “spoiler” that the 300 trillionth digit of pi is 5, but that was already relatively easy to compute using the Borwein-Bailey-Plouffe algorithm and was probably already known. The BBP algorithm lets you compute a specific digit like the 300 trillionth, using fairly little memory and much less compute time than computing all of the digits.
https://en.wikipedia.org/wiki/Bailey–Borwein–Plouffe_formula
I wanted to just post the video, which has a lot more information (though not the kind of info you’re looking for), but I didn’t know if an LTT video was an “official” enough source for this community.
I suppose this was probably the first time that all of the digits of pi up to 300 trillion were calculated, even if the 300 trillionth specifically was already known.
Yes, that’s the idea, it’s just that the “spoiler” likely only revealed something that was already known (that specific digit), or at any rate, something that could be computed on a much smaller computer and in less time. Mostly though, that’s a bit of mathematically interesting info.
I don’t feel like watching a video but maybe there will be a more informative article sometime. I wonder if they used some existing software like Y-cruncher: https://en.wikipedia.org/wiki/Y-cruncher
The calculation technically only takes 12 straight days to compute, but they had many interruptions over the process, sometimes having to fully restart the whole calculation.
They did use Y-cruncher.
Edit: Some other fun tidbits: most of that 2.2 petabytes of storage wasn’t actually used to store the 300 trillion digits itself - that number of digits fits in like 170 terabytes (which LTT is thinking of making available as a download, lol) - it’s actually used as pseudo-ram during the actual calculation.
Cool, yeah, the digits themselves are at most 0.5 byte each ;). I don’t know enough about the higher level algorithm to say exactly how the rest of the storage is being used. There is a book called “Pi and the AGM” about pi computation and similar algorithms that is supposed to be really good, but it looks over my head mathematically.