4 ms·
> On these computers, I could factor a general number with around 70 decimal digits in a reasonable amount of time (like overnight). What’s the comparable figu
by SilasX 6y ago
> On these computers, I could factor a general number with around 70 decimal digits in a reasonable amount of time (like overnight).
What’s the comparable figure you could get on typical hardware in today’s university computing clusters or computer labs?
- taldo 6y agoOr on a single modern smartphone?
- andai 6y agoOn that note, I'd like to share a clip about how fast modern machines are relative to early 90s supercomputers (the relevant part is in the first 5 minutes): https://youtube.com/watch?v=oJ4GcZs7y6g https://youtube.com/watch?v=oJ4GcZs7y6g
- leephillips 6y agoHa, I did a small bunch of calculations on the CM5. Thanks for the memories.
- elengyel 6y agoI'd very much like to revive my old code (which I still have) at some point and see how well it runs on modern computers. My guess is that a typical 64-bit ~3 GHz quad-core machine could accomplish the same task in a few minutes today.
- SilasX 6y agoHate to be the choosing beggar, and I appreciate all the answers, but ... everyone is answering about how long that 70 digit job would take now, when what I meant was, how big a number could you factor “overnight” with similar cost hardware.
- zsmi 6y agoNot exactly the same, but close. https://github.com/eniac/faas https://github.com/eniac/faas The purpose of the FaaS (Factoring as a Service) project is to demonstrate that 512-bit integers can be factored in only a few hours, for less than $100 of compute time in a public cloud environment. 512b = 155 decimal digits.
- SilasX 6y agoCool, thanks!
- acchow 6y agoA quick lookup for CPU speeds of yesteryear shows the Motorola 68040 in those macs did about 35 MFLOPS [1]. If you could parallelize this program to use all 2.6 TFLOPS in a Macbook Air M1's 8-core GPU, you're seeing about 75,000x speed improvement. So a 12 hour "overnight" job may take just over half a second. [1] https://tech-insider.org/mac/research/1991/1021-e.html https://tech-insider.org/mac/research/1991/1021-e.html
- throw5away 6y agoI generated two random 35 digit primes, multiplied them, and then tossed the product into the first hit for "factor integer online": https://www.alpertron.com.ar/ECM.HTM https://www.alpertron.com.ar/ECM.HTM 1731 322587 637083 705865 442033 654804 904216 446486 784497 444181 466938 498269 (70 digits) = 25317 847509 490819 861309 522806 413689 (35 digits) × 68383 482718 586893 688113 139227 257221 (35 digits) Time elapsed: 0d 0h 0m 23.8s This is in JavaScript on a single core on my laptop.