mersenneforum.org  

Go Back   mersenneforum.org > Factoring Projects > Factoring

Reply
 
Thread Tools
Old 2016-09-01, 12:54   #89
GP2
 
GP2's Avatar
 
Sep 2003

29×89 Posts
Default

Quote:
Originally Posted by xilman View Post
The work curve has a very flat minimum. It doesn't matter very much whether you run more curves at a lower B1 or fewer at a higher one, as long as you don't push it too far. To an excellent approximation, the product B1*#curves is the figure of merit.
Does the above apply only to stage one?

What about the B2 bound?

For Pāˆ’1, I think it normally doesn't find factors beyond the bound B2, unless exceptionally by Brent-Suyama extension.

Does ECM routinely find factors beyond the B2 bound? What is the effect of increasing the B2 bound, does it merely increase the probability of finding a factor within the B2 bound?
GP2 is offline   Reply With Quote
Old 2016-09-19, 15:13   #90
Raman
Noodles
 
Raman's Avatar
 
"Mr. Tuch"
Dec 2007
Chennai, India

3×419 Posts
Default

I don't think that it will be possible to factor completely any more Fermat numbers with the current technology.
Either computational power needs to be increased either by using multiple computers or by using micro processor speed or improvements with in factoring algorithms need to be made or quantum computers - Shor's algorithm should need to be built out effectively and then efficiently up (Integer Factorization Problem Improvements ā‡” Discrete Logarithm Problem Improvements)! (Google Search Engine features much more symbols than character map).
If 2,1024+ did not drop off a small 40-digit factor, it would be only factored recently, right now. 2,1039-, first kilo bit SNFS factorization had been done how ever as early as Monday 21 May 2007.
It had been very lucky enough that the 564 digit cofactor of 2,2048+ is being prime number candidate, or it would also have been infeasible - computationally out of reach too, right now! Given that fixed penultimate prime factor candidate of 2,2048+ which is being a smaller number candidate - not - not - larger number candidate!
Raman is offline   Reply With Quote
Old 2016-09-19, 20:41   #91
henryzz
Just call me Henry
 
henryzz's Avatar
 
"David"
Sep 2007
Cambridge (GMT/BST)

34·71 Posts
Default

Quote:
Originally Posted by Raman View Post
I don't think that it will be possible to factor completely any more Fermat numbers with the current technology.
Either computational power needs to be increased either by using multiple computers or by using micro processor speed or improvements with in factoring algorithms need to be made or quantum computers - Shor's algorithm should need to be built out effectively and then efficiently up (Integer Factorization Problem Improvements ā‡” Discrete Logarithm Problem Improvements)! (Google Search Engine features much more symbols than character map).
If 2,1024+ did not drop off a small 40-digit factor, it would be only factored recently, right now. 2,1039-, first kilo bit SNFS factorization had been done how ever as early as Monday 21 May 2007.
It had been very lucky enough that the 564 digit cofactor of 2,2048+ is being prime number candidate, or it would also have been infeasible - computationally out of reach too, right now! Given that fixed penultimate prime factor candidate of 2,2048+ which is being a smaller number candidate - not - not - larger number candidate!
In reality it is just a matter of luck. We find a few fermat factors each year. Any one of these could leave a prp cofactor. This happens for Mersenne numbers. The issue is that the fermat numbers get bigger much quicker and less factors are found.
I don't know whether the cofactor has to be proven prime here. That would limit us to rather a small number of candidates.
henryzz is online now   Reply With Quote
Old 2016-09-22, 15:30   #92
richs
 
richs's Avatar
 
"Rich"
Aug 2002
Benicia, California

2×32×5×13 Posts
Default

I ran two curves on F25 and Prime95 reported on 19 September, but the counter on the ECM Report page has not incremented from 450.

[Mon Sep 19 18:41:52 2016]
UID: richs/Rich_-_Laptop, F25 completed 2 ECM curves, B1=1000000, B2=1000000, We4: 64119540, AID: B36AA7689965395BB40858081FC4****

What did I do wrong?
richs is offline   Reply With Quote
Old 2016-09-22, 16:39   #93
Prime95
P90 years forever!
 
Prime95's Avatar
 
Aug 2002
Yeehaw, FL

7,159 Posts
Default

Looks like there was no stage 2 run. Two curves at B1=1M were not enough to count as 1 curve at B1=1M, B2=100M
Prime95 is online now   Reply With Quote
Old 2016-09-28, 14:51   #94
jwaltos
 
jwaltos's Avatar
 
Apr 2012

33·13 Posts
Default

I'm still pursuing a particular approach to a (new) completed Fermat number factorization but the solution timeline is now tenuous. Is there any optimism, probabilistically speaking, of obtaining a factorization via conventional approaches?
jwaltos is offline   Reply With Quote
Old 2016-09-29, 03:48   #95
jwaltos
 
jwaltos's Avatar
 
Apr 2012

15F16 Posts
Unhappy

Ok. Asked and answered.
jwaltos is offline   Reply With Quote
Old 2016-09-29, 07:49   #96
GP2
 
GP2's Avatar
 
Sep 2003

1010000101012 Posts
Default

Quote:
Originally Posted by jwaltos View Post
I'm still pursuing a particular approach to a (new) completed Fermat number factorization but the solution timeline is now tenuous. Is there any optimism, probabilistically speaking, of obtaining a factorization via conventional approaches?
Monitor the ECM progress page and you'll see the number of curves tested increasing by a few (less than ten) on most days. However, it will probably need tens of thousands of curves or hundreds of thousands.... so it's liable to take a while, and that's a necessary but not necessarily sufficient condition.

On a 2.4 GHz Haswell machine, each curve for F12 takes maybe 3 hours and each curve for F13 takes maybe an hour (using mprime).
GP2 is offline   Reply With Quote
Old 2016-09-29, 12:38   #97
pinhodecarlos
 
pinhodecarlos's Avatar
 
"Carlos Pinho"
Oct 2011
Milton Keynes, UK

12A716 Posts
Default

In a few hours I will finish a run of 10 curves for F12. Will Prime95 automatically submit the results into server despite the fact that I didn't setup my client ID on it or should I manually submit them onto Prime95 webpage at ''MANUAL TESTING/RESULTS'' submission form?

Also how can I set on the txt files stage 2 to use 4GB? Running two cores on a 16GB machine.

Thank you in advance.

Last fiddled with by pinhodecarlos on 2016-09-29 at 12:44
pinhodecarlos is online now   Reply With Quote
Old 2016-09-29, 13:06   #98
GP2
 
GP2's Avatar
 
Sep 2003

50258 Posts
Default

Quote:
Originally Posted by pinhodecarlos View Post
In a few hours I will finish a run of 10 curves for F12. Will Prime95 automatically submit the results into server despite the fact that I didn't setup my client ID on it or should I manually submit them onto Prime95 webpage at ''MANUAL TESTING/RESULTS'' submission form?
By default, your prime.txt file will say UsePrimenet=1, unless you set it differently. If so, the results will be automatically submitted.

Quote:
Originally Posted by pinhodecarlos View Post
Also how can I set on the txt files stage 2 to use 4GB? Running two cores on a 16GB machine.
If you are asking how to use GMP-ECM for stage 2, I think it involves setting GmpEcmHook=1 as described in undoc.txt, and some discussion can be found in this thread.
GP2 is offline   Reply With Quote
Old 2016-09-29, 18:51   #99
pinhodecarlos
 
pinhodecarlos's Avatar
 
"Carlos Pinho"
Oct 2011
Milton Keynes, UK

52·191 Posts
Default

I've uploaded 10 curves for F12. More to come next week.

Code:
[Thu Sep 29 19:34:22 2016]
F12 completed 5 ECM curves, B1=800000000, B2=80000000000, We4: D02C2838
F12 completed 5 ECM curves, B1=800000000, B2=80000000000, We4: D02C2838
pinhodecarlos is online now   Reply With Quote
Reply

Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Weird freezing error, desperate for a solution. jasong Lounge 5 2016-11-18 00:43
September 2016 Batalov Puzzles 8 2016-10-04 14:10
YAFU Poly Select Deadline amphoria YAFU 22 2016-09-17 09:47
Official Ernst (ewmayer) / Richard (cheesehead) feud thread cheesehead Soap Box 50 2014-06-30 01:06
Appeal for machines dave_dm GMP-ECM 0 2005-06-29 02:23

All times are UTC. The time now is 16:53.

Sun Nov 29 16:53:44 UTC 2020 up 80 days, 14:04, 4 users, load averages: 1.20, 1.06, 1.03

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.

This forum has received and complied with 0 (zero) government requests for information.

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation.
A copy of the license is included in the FAQ.