mersenneforum.org  

Go Back   mersenneforum.org > Factoring Projects > Aliquot Sequences

Reply
 
Thread Tools
Old 2011-02-23, 10:51   #1
Syd
 
Syd's Avatar
 
Sep 2008
Krefeld, Germany

23010 Posts
Default need some advice: gnfs C164 from 162126:i4274

I think about gnfs'ing this one.

GMP-ECM failed to find a factor, did 2k curves at B1=110M, B2=default. Enough I guess?

This poly came up quite early:

Code:
# norm 6.257845e-16 alpha -6.143336 e 8.508e-13 rroots 3
skew: 20836454.90
c0:  15679837385732869622529327137425328966325
c1:  634300527717663660453424437257893
c2: -171419531873315925748960917
c3: -11750273807052233661
c4: -729125354572
c5:  12036
Y0: -74454053249923833901454562105026
Y1:  442492487829916909
Looks good enough to me.

I would have chosen:
rlim: 30M
alim: 30M
lpbr: 31
lpba: 31
mfbr: 62
mfba: 62
rlambda: 2.7
alambda: 2.7

and the 15e-siever, sieving from 15M up, algebraic side only.

Any comments/advice on this one?
Syd is offline   Reply With Quote
Old 2011-02-23, 12:18   #2
schickel
 
schickel's Avatar
 
"Frank <^>"
Dec 2004
CDP Janesville

2×1,049 Posts
Default

Quote:
Originally Posted by Syd View Post
I think about gnfs'ing this one.

[ ... ]

Any comments/advice on this one?
No advice, just a question: do you want to do this as a solo project or shall we make it another team effort?
schickel is offline   Reply With Quote
Old 2011-02-23, 12:44   #3
Syd
 
Syd's Avatar
 
Sep 2008
Krefeld, Germany

2×5×23 Posts
Default

If anyone is interested in participating - sure, lets make it another team sieve! I can also do the postprocessing afterwards.
Syd is offline   Reply With Quote
Old 2011-02-23, 14:10   #4
FactorEyes
 
FactorEyes's Avatar
 
Oct 2006
vomit_frame_pointer

35610 Posts
Default

Quote:
Originally Posted by Syd View Post
Any comments/advice on this one?
Do more ECM. 2000 curves at 11e7 is nowhere near enough.

I'd do another 6000 before sieving.

Last fiddled with by FactorEyes on 2011-02-23 at 14:23
FactorEyes is offline   Reply With Quote
Old 2011-02-23, 15:01   #5
Syd
 
Syd's Avatar
 
Sep 2008
Krefeld, Germany

2×5×23 Posts
Default

Quote:
Originally Posted by FactorEyes View Post
Do more ECM. 2000 curves at 11e7 is nowhere near enough.

I'd do another 6000 before sieving.
Thank you! I'll do more ecm curves now. 6000 will take some time ..
Syd is offline   Reply With Quote
Old 2011-02-24, 07:40   #6
debrouxl
 
debrouxl's Avatar
 
Sep 2009

977 Posts
Default

Judging by previous team sievings for Aliquot 4788, a 31-bit LPs task with 15e might be slightly aggressive for a C164 GNFS. AFAICT, 30-bit LPs task with 15e, or a 31-bit LPs task with 14e, would be more in line with previous sievings.

But yeah, for now, this number needs more ECM, until at least t50.
debrouxl is offline   Reply With Quote
Old 2011-03-14, 13:58   #7
Syd
 
Syd's Avatar
 
Sep 2008
Krefeld, Germany

E616 Posts
Default

I just finished this one using 14e and 31bit LP, needed 160M relations to build a 9,3M-matrix. Almost a nice split! Maybe rlim/alim was a little too low, but still quite fast.

prp81 factor: 581961354791396552117021757640957983720026694275473538439704344834014177515059043
prp83 factor: 47318351303826266855330899870715547902208735682285930149249021834006959676298350389

Last fiddled with by Syd on 2011-03-14 at 14:50 Reason: typo
Syd is offline   Reply With Quote
Old 2011-03-14, 18:35   #8
schickel
 
schickel's Avatar
 
"Frank <^>"
Dec 2004
CDP Janesville

40628 Posts
Default

Quote:
Originally Posted by Syd View Post
I just finished this one using 14e and 31bit LP, needed 160M relations to build a 9,3M-matrix. Almost a nice split! Maybe rlim/alim was a little too low, but still quite fast.

prp81 factor: 581961354791396552117021757640957983720026694275473538439704344834014177515059043
prp83 factor: 47318351303826266855330899870715547902208735682285930149249021834006959676298350389
Nice split!

schickel is offline   Reply With Quote
Reply

Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Team sieve #43: C164 from 4788:i5194 -- FINISHED RichD Aliquot Sequences 9 2014-01-12 11:09
Advice for large GNFS jobs? WraithX Factoring 59 2013-07-30 01:13
Seeking GNFS factoring advice... WraithX Msieve 18 2012-05-20 22:19
Advice for PSU em99010pepe Hardware 1 2010-01-31 23:48
Looking for advice for a new PC.... petrw1 Hardware 39 2009-07-11 13:38

All times are UTC. The time now is 23:32.

Fri Oct 30 23:32:41 UTC 2020 up 50 days, 20:43, 2 users, load averages: 2.18, 2.23, 2.08

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.