Prez wrote on Mar 15, 2021, 03:02:
I wonder how far out Google's easter egg calculates pi...
If I remember right didn't some massive super computer calculate it out to trillions of decimal places?
Someone at Google arranged to do it with 25 virtual machines from their cloud a couple years ago, targeted 31.415 trillion digits and completed the calc in 121 days, just in time to promote it for Pi Day 2019. But that wasn't the record for long, turns out some random IT guy was planning to go for a new record around that same time. He chuckled and said "that's cute" to the Google record announcement and proceeded to spend 303 days calculating 50 trillion digits on his own home server. I'm sure someone else is working on the next record attempt right now... Google or Amazon or whoever could smash it quickly if they wanted to, but there's not much for them to gain from it.
It's not even that the calculation takes an insane amount of CPU power, the 50 trillion record was done on 4x Intel Xeons (total 60c/120t @ 2.5GHz). I mean, it did take almost a year, but that's no supercomputer. The bigger issue is memory and storage -- his server had 320GB of DDR3-8500, 72TB disk space for the swap files (calc required about 280TB of total data), then another 40TB disk space just to store the results, the actual 50 trillion digits saved as compressed text. The transfer speed of the disks being used for the calculations is the real bottleneck for how long the whole thing takes, the numbers are way too big for it all to be done in even that much RAM. He started out being limited to 3Gbps SATA throughput for 12x 7200 RPM drives, but upgraded midway to 6Gbps and they say he shaved a couple months off of the total duration.
The program everyone uses for this is called y-cruncher, it's like a souped-up version of that SuperPi program people used to use for benchmarking, but this one supports all sorts of different algorithms for various mathematical constants. They keep track of the records on this page here
, with links to verification files and other proofs, blog posts from the record holders, etc. It's very popular nowadays for stress testing and benchmarking CPUs, but for that it's just about how fast you can do smaller amounts like 1-10 billion digits, since that's how much a gaming rig would be able to fit into RAM (and so your disk space isn't totally crushed by writing larger results).This comment was edited on Mar 15, 2021, 04:23.