20201104, 03:02  #1 
Feb 2019
China
59 Posts 
who knows Ryan Propper?
https://members.loria.fr/PZimmermann/records/top50.html
http://www.prothsearch.com/fermat.html I know his name from that two website , he find the factor of 7^337+1, 16559819925107279963180573885975861071762981898238616724384425798932514688349020287 I check it with sigma 3882127693,but it works very slow on my computer with one elliptic curve ,how long did he cost to get that factor ? my pc computer Windows 7 64bit ,what is his hardware ? 
20201104, 04:00  #2  
"Serge"
Mar 2008
Phi(4,2^7658614+1)/2
9,257 Posts 
Quote:
http://factordb.com/index.php?id=1100000000632146801 then click on green arrow next to "ECM" ... or here, then click on the link to order value of the curve, then you will find that with this sigma you can use B1 = 115e7 and B2 = 8e12. This will save you a lot of running time to confirm that this is the correct factor by ECM. Of course you can also check that it is indeed a factor much faster. 

20201104, 07:58  #3  
Feb 2019
China
59 Posts 
Quote:


20201104, 10:34  #4 
"Oliver"
Sep 2017
Porta Westfalica, DE
2×7×29 Posts 
I'm quite sure he will not give you the address where his hardware is sitting.

20201104, 20:28  #5 
Jun 2012
Boulder, CO
5·7^{2} Posts 

20201104, 21:03  #6  
"Serge"
Mar 2008
Phi(4,2^7658614+1)/2
9,257 Posts 
Go here and rent a node. It will not be very different. x86_64 GNU/Linux, Xeon 8xxx CPU @ 3.00  3.40 GHz or similar. Maybe newer, maybe slightly older. It doesn't matter much.
Quote:
Just like with a car, saying 'but I don't know how to drive it' (or 'I don't know how to use EC2') is unacceptable in 2020. Learn! Pick up a book, watch a YT video, take a coursera course. 

20201105, 00:02  #7 
Feb 2017
Nowhere
1040_{16} Posts 
The 83digit factor of 7^337 + 1 is listed as having been found seven years ago! It is possible the same hardware is still merrily crunching out results, but you might want to consider the possibility that the user may be using something different now.
Heck, for all I know, the hardware that found that factor barely finished the computation and output the result, before melting into a pool of slag which, after cooling off, became a piece of lawn sculpture. In that case, knowing where it is wouldn't do you much good. 
20201105, 00:55  #8 
Feb 2019
China
73_{8} Posts 

20201105, 01:26  #9  
Feb 2019
China
59 Posts 
Quote:
I have one personal computer ,Windows 7 operating system ,but works slowly , so I want to know what kind of hardware helps Ryan Propper to get that 83digits factor Last fiddled with by bbb120 on 20201105 at 01:27 

20201105, 01:27  #10 
"Mike"
Aug 2002
2^{2}×5×397 Posts 

20201105, 01:38  #11 
"Serge"
Mar 2008
Phi(4,2^7658614+1)/2
9257_{10} Posts 
It takes about 2 hrs for the Stage 1 and another hour for Stage 2 (and not too much RAM) to reproduce this ECM hit.
As it was originally found, it was perhaps a 1215 CPUhour run, you know, 7 yrs ago, per curve  or in this case the lucky curve. Code:
GMPECM 7.0.4 [configured with GMP 6.1.2, enableasmredc] [ECM] Tuned for x86_64/k8/params.h Running on ip1723127255 Input number is (7^337+1)/808161122051378212567896018011524822258323205672 (237 digits) Using MODMULN [mulredc:1, sqrredc:1] Using B1=1150000000, B2=8000000000000, polynomial Dickson(30), sigma=0:3882127693 dF=524288, k=3, d=5705700, d2=17, i0=185 Expected number of curves to find a factor of n digits: 35 40 45 50 55 60 65 70 75 80 15 47 162 624 2636 12164 60183 318529 1793599 1.1e+07 Step 1 took 7573043ms Using 28 small primes for NTT Estimated memory usage: 2.64GB Initializing tables of differences for F took 503ms Computing roots of F took 89201ms Building F from its roots took 159581ms Computing 1/F took 79996ms Initializing table of differences for G took 694ms Computing roots of G took 70110ms Building G from its roots took 167132ms Computing roots of G took 69881ms Building G from its roots took 167327ms Computing G * H took 39791ms Reducing G * H mod F took 39970ms Computing roots of G took 69782ms Building G from its roots took 168006ms Computing G * H took 39928ms Reducing G * H mod F took 39915ms Computing polyeval(F,G) took 312713ms Computing product of all F(g_i) took 367ms Step 2 took 1517151ms ********** Factor found in step 2: 16559819925107279963180573885975861071762981898238616724384425798932514688349020287 Found prime factor of 83 digits: 16559819925107279963180573885975861071762981898238616724384425798932514688349020287 Prime cofactor ((7^337+1)/808161122051378212567896018011524822258323205672)/16559819925107279963180573885975861071762981898238616724384425798932514688349020287 has 155 digits Peak memory usage: 3194MB 