mersenneforum.org  

Go Back   mersenneforum.org > Great Internet Mersenne Prime Search > Hardware > GPU Computing

Reply
 
Thread Tools
Old 2011-11-17, 07:36   #1
Uncwilly
6809 > 6502
 
Uncwilly's Avatar
 
"""""""""""""""""""
Aug 2003
101×103 Posts

207128 Posts
Default GPU attack on double Mersennes?

MM61 and MM127 have been vexing us for a while. Anyone think that an attack on these numbers using GPU's to TF is worth the effort? (This excludes RDS, as I already know his opinion.) The current versions of mfaktx can't do numbers that large (am I right?)
Uncwilly is offline   Reply With Quote
Old 2011-11-17, 07:52   #2
LaurV
Romulan Interpreter
 
LaurV's Avatar
 
Jun 2011
Thailand

2·13·337 Posts
Default

Someone checked already and there are no known factors below 100 bits or so. I think the value is 10^33 times something. I think it is not easy to go above that value, even with a GPU.
LaurV is offline   Reply With Quote
Old 2011-11-17, 09:46   #3
davieddy
 
davieddy's Avatar
 
"Lucan"
Dec 2006
England

2·3·13·83 Posts
Default

Quote:
Originally Posted by Uncwilly View Post
MM61 and MM127 have been vexing us for a while. Anyone think that an attack on these numbers using GPU's to TF is worth the effort? (This excludes RDS, as I already know his opinion.) The current versions of mfaktx can't do numbers that large (am I right?)
If MM61 counts as a double mersenne, why not MM89 and MM107 ?

David
davieddy is offline   Reply With Quote
Old 2011-11-17, 09:53   #4
Brian-E
 
Brian-E's Avatar
 
"Brian"
Jul 2007
The Netherlands

326610 Posts
Default

Quote:
Originally Posted by LaurV View Post
Someone checked already and there are no known factors below 100 bits or so. I think the value is 10^33 times something. I think it is not easy to go above that value, even with a GPU.
This thread discusses some of the progress if you take care to avoid the crank postings in it. In the case of MM127 it is apparently more like no factor to about 176 bits thanks to Ernst Mayer.

It would be a lucky strike to discover a factor in the several extra bit levels that a concerted effort with GPU's might achieve. The most likely result of the effort would still be "no factor found". But that doesn't say it that it isn't worth the effort.
Brian-E is offline   Reply With Quote
Old 2011-11-17, 10:00   #5
LaurV
Romulan Interpreter
 
LaurV's Avatar
 
Jun 2011
Thailand

876210 Posts
Default

Quote:
Originally Posted by davieddy View Post
If MM61 counts as a double mersenne, why not MM89 and MM107 ?

David
And why not MM127? (which I believe is prime, I am a big fan of Catalan conjecture, and hope that all numbers in the sequence are prime :D). Now joking apart, I assume we would have more chances to find a (small) factor of MM89 and MM107 (as for MM61 and MM127 there is a lot of work done, and the lower bounds for factors are already incredible high). Assuming we have the (software) tools to play with them.
LaurV is offline   Reply With Quote
Old 2011-11-17, 10:19   #6
davieddy
 
davieddy's Avatar
 
"Lucan"
Dec 2006
England

2×3×13×83 Posts
Default

Quote:
Originally Posted by LaurV View Post
And why not MM127?
No reason at all, except that Uncwilly had already mentioned it,
and 127 is 2^7 - 1 whereas 61 is 2^6 - 3.
davieddy is offline   Reply With Quote
Old 2011-11-18, 01:30   #7
Christenson
 
Christenson's Avatar
 
Dec 2010
Monticello

5×359 Posts
Default

mfaktc would be the starting point for the software for such a GPU attack...but I don't think it handles FCs above about 90 bits.

So someone would need to take that up, and I'm not volunteering at the moment.
Christenson is offline   Reply With Quote
Old 2011-11-18, 02:23   #8
Dubslow
Basketry That Evening!
 
Dubslow's Avatar
 
"Bunslow the Bold"
Jun 2011
40<A<43 -89<O<-88

3·29·83 Posts
Default

https://sites.google.com/site/anthon...s/mm61prog.htm

Current progress as of half a month ago. It also seems our very own Ernest Mayer found a factor of MM31 some years ago.
Dubslow is offline   Reply With Quote
Old 2011-11-18, 02:38   #9
Uncwilly
6809 > 6502
 
Uncwilly's Avatar
 
"""""""""""""""""""
Aug 2003
101×103 Posts

100001110010102 Posts
Default

Quote:
Originally Posted by Dubslow View Post
It also seems our very own Ernest Mayer found a factor of MM31 some years ago.
That is exactly why I did not mention it in my original post.

Last fiddled with by Uncwilly on 2011-11-18 at 02:38
Uncwilly is offline   Reply With Quote
Old 2011-11-18, 02:39   #10
davieddy
 
davieddy's Avatar
 
"Lucan"
Dec 2006
England

11001010010102 Posts
Default The Importance of not being Ernest

Quote:
Originally Posted by Dubslow View Post
https://sites.google.com/site/anthon...s/mm61prog.htm

Current progress as of half a month ago. It also seems our very own Ernest Mayer found a factor of MM31 some years ago.
Note also that Alex Kruppa proved F31
composite even earlier.

David

Last fiddled with by davieddy on 2011-11-18 at 02:47
davieddy is offline   Reply With Quote
Old 2013-09-07, 14:41   #11
lbh134679
 
Sep 2013
China

22 Posts
Default

A factor of MM61 and MM127 can be found, I guess, above 10^100 or even 10^1000. Well, probably.
lbh134679 is offline   Reply With Quote
Reply

Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Nuke attack - run or hide? MooMoo2 Soap Box 40 2018-01-19 23:48
Let's attack the Bayesian-ECM-bounds again fivemack Math 33 2017-02-10 00:10
Attack of the Cosmic Rays S485122 Hardware 3 2010-08-24 01:19
Attack of the Killer Zombies ewmayer Lounge 12 2007-01-30 05:56
Factoring Double mersennes Citrix Miscellaneous Math 2 2005-10-04 08:08

All times are UTC. The time now is 17:25.

Thu Oct 1 17:25:20 UTC 2020 up 21 days, 14:36, 0 users, load averages: 1.64, 1.59, 1.60

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.