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-   -   Cooperative Agreement or Capitalist Takeover? You decide! (https://www.mersenneforum.org/showthread.php?t=16850)

ATH 2012-05-29 02:16

George should make a Prime95 version for BOINC and give people lots of credits so we get thousands of new contributors :smile:

Batalov 2012-05-29 02:47

It would be like Newegg getting new customers by opening an ebay storefront. Seems utterly redundant... only it isn't!

Dubslow 2012-05-29 03:06

[QUOTE=davieddy;300564] George has the definitive(?) database re the state of the art.[/QUOTE]
State of the art database? Well... I'll give him state of the art software :smile:
(Awesome software, hands down.)

davieddy 2012-05-29 03:14

[QUOTE=ATH;300574]George should make a Prime95 version for BOINC and give people lots of credits so we get thousands of new contributors :smile:[/QUOTE]
What are "they" on?

Re "credit", all I care about is maximizing the probability of finding another MP before I die.

bloodIce 2012-05-29 11:52

Two new factors, but there are probably many others
 
They have two factors for small exponents on their webpage ([URL]http://mersenneathome.net/[/URL]), which are not in the GIMPS database:

[QUOTE]For [I]p=2100451[/I], [I]M(p)[/I] is divisible by [I]63923221582748657[/I]. The divisor found by:[LIST][*][URL="http://mersenneathome.net/show_user.php?userid=1727"][B]tng*[/B][/URL] from team [URL="http://mersenneathome.net/team_display.php?teamid=438"]Sicituradastra[/URL] and,[*][URL="http://mersenneathome.net/show_user.php?userid=2014"][B]vanos0512[/B][/URL] from team [URL="http://mersenneathome.net/team_display.php?teamid=1187"]BOINC@Taiwan[/URL][/LIST]For [I]p=2102207[/I], [I]M(p)[/I] is divisible by [I]124414352434216087[/I]. The divisor found by:
[LIST][*][URL="http://mersenneathome.net/show_user.php?userid=3017"][B]matszpk[/B][/URL] and,[*][URL="http://mersenneathome.net/show_user.php?userid=3939"][B]ximian[/B][/URL], both from team [URL="http://mersenneathome.net/team_display.php?teamid=97"]BOINC@Poland[/URL].[/LIST][/QUOTE]How to deal with that. Should we submit them to GIMPS or those factors are not "ours"?

xilman 2012-05-29 12:14

[QUOTE=bloodIce;300608]They have two factors for small exponents on their webpage ([URL]http://mersenneathome.net/[/URL]), which are not in the GIMPS database:

How to deal with that. Should we submit them to GIMPS or those factors are not "ours"?[/QUOTE]Surely the appropriate way would be to send a polite request that they be added into the GIMPS database, with the offer for one of the GIMPS team to submit them if the finders' prefer, and that GIMPS credit be given to the finders.

Paul

bloodIce 2012-05-29 13:49

Although, it takes about 0.00913267 GHz days to produce those factors (which are around 56-57 bits). I thought that the factorization to 2^60 was already done for those two exponents ([I]2102207[/I] and [I]2100451),[/I] but obviously not.

KEP 2012-05-29 15:41

Well guys, I got this reply from Bobrecki:
----------------------------------------------------------------------------
Hello KEP,

Hello Sebastian
...
1. Is all candidates previously factored by GIMPs removed from testing?

The majority of it. But probably an insignificant percentage of the work may overlap.
----------------------------------------------------------------------------

It was given to me as a reply to a PM. I'm really not understanding if George should fail to get a reply if he sends a PM at the mersenneathome.net website, since I got reply in less than 8 hours. But as you can see it appears that all candidates previously factored by GIMPs has been removed from the database. However it appears that the remaining candidates were left for further TF without concern to previous TF depths. So maybe a consideration should be to convince Bobrecki to do 1 of following suggestions:

1. Give people the possibility of only doing TF of candidates for n>1G (All 3 phases)
2. Only to do TF that has not allready been done by GIMPs (thereby also consider current TF bit depth)
3. To coordinate the future workload with George or other people at GIMPs such that new discoveries are made by both projects. Discoveries wich can then be exported to one anothers different database.

Well that's my thoughts. I'm unfortunantly not able to speak Polish, but with todays recent findings of 2 unknown factors, it actually shows that there may be something to look for afterall, despite those different TF ranges has already been extensively tested previously.

Take care

Kenneth

chalsall 2012-05-29 16:02

[QUOTE=KEP;300617]...but with todays recent findings of 2 unknown factors, it actually shows that there may be something to look for afterall, despite those different TF ranges has already been extensively tested previously.[/QUOTE]

In Science, independent work is welcomed, not discouraged.

Dubslow 2012-05-29 17:52

[QUOTE=bloodIce;300613]Although, it takes about 0.00913267 GHz days to produce those factors (which are around 56-57 bits). I thought that the factorization to 2^60 was already done for those two exponents ([I]2102207[/I] and [I]2100451),[/I] but obviously not.[/QUOTE]

We've found that if bad hardware is used, sometimes factors are missed, when they [I]should[/I] have been found. A few members of this forum like to go back to low exponents that have already been double-LLed and rerun P-1, if it was skipped or done poorly the first time; occasionally they find factors that [I]should[/I] have been found the first time, but due to hardware errors were not found. James Heinrich maintains a list of such exponents [URL="http://mersenne-aries.sili.net/p1missed.php"]here[/URL].

Neither trial factoring nor P-1 factoring are double checked by GIMPS, because the effort/value ratio is far too high compared to just running two LL tests. As far as I know, there isn't anybody that is redoing TF on very low exponents. The nature of the P-1 algorithm means that extending the bounds will find smaller factors anyways, whereas doing TF from 2^60 to 2^61 will not find any missed factors <2^60.

Addendum: [URL="http://www.mersenneforum.org/showthread.php?p=279251#post279251"]Here[/URL]'s some discussion of should-have-been-found-the-first-time P-1 factors.

chalsall 2012-05-29 17:58

[QUOTE=Dubslow;300630]We've found that if bad hardware is used, sometimes factors are missed, when they [I]should[/I] have been found.[/QUOTE]

We've also found that the software provided by GIMPS did not always find the factors which should have been found....


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