Coordination thread for redoing P-1 factoring

[c10ck3r]

Originally Posted by masser

New (to me) result feedback:

Splitting composite factor 72115741492408141371057158919540730748664584042639 into:
* 57330969015562354090032601
* 1257884573219624043651239

https://www.mersenne.org/report_expo...2645329&full=1

And a juicy B-S factor at that. The smaller of the two would otherwise require B2=809M instead of the 50M it received. In fact, if you were running with that high of B2, you likely would've only found the larger factor, as it would be found in stage 1 with a B1 of 11M. Very cool how that worked out!

[masser]

Originally Posted by masser

I think 2.6M will be very close to the 1999 unfactored goal after my initial pass is complete. If necessary, finishing that range with a second pass shouldn't be too difficult. I should be finished with 2.6M by the end of 2019.

2.8M will take a little longer with my measly i5, but I'll keep plugging away at it. The next pass over that range will be a little more strategic.

SRJ2877 and I have gotten the 2.6M range below 2000 unfactored. I will now "unreserve" the 2.6M range. The last few factors were found by running ECM curves. I ran 8396 curves at the 25-digit bounds (B1=50K, B2=5M) and found 7 factors. This took 23.25 days, so about two factors per week for me.

I will now work on a second pass of P-1 factoring over the 2.8M range. After digging around the forum a little bit more, I found this post that recommended spending 5-6% of the ECM effort on P-1 factoring. Getting the 2.8M range below 2000 unfactored will likely require additional ECM work after this pass of P-1 factoring.

[masser]

Originally Posted by masser

SRJ2877 and I have gotten the 2.6M range below 2000 unfactored. I will now "unreserve" the 2.6M range.

I will now work on a second pass of P-1 factoring over the 2.8M range.

The 2.8M range now has less than 2000 unfactored. I will "unreserve" and move on to the 2.9M range.

[masser]

2.9M now has less than 2000 unfactored. Pursuing the white whale of 14.0M next...

[petrw1]

Originally Posted by masser

2.9M now has less than 2000 unfactored. Pursuing the white whale of 14.0M next...

That's ambitious. Good for you.
I probably don't have to tell you that you will need aggressive B1/B2 values.

Enjoy.

[masser]

I have the stage 1 P-1 savefiles for the factoring work I completed in the 2.6M, 2.8M and 2.9M ranges.

If someone were interested in further factoring the candidates in those ranges, the savefiles might save them quite a bit of work.

I'm certain this has been discussed on the forum in the past, but currently, there is no online repository for savefiles, right?

My machine is (slowly) running out of storage space, so I might have to begin deleting the savefiles. It would be nice to have a place to stow them for future interested parties.

[petrw1]

Originally Posted by masser

I have the stage 1 P-1 savefiles for the factoring work I completed in the 2.6M, 2.8M and 2.9M ranges.

If someone were interested in further factoring the candidates in those ranges, the savefiles might save them quite a bit of work.

I'm certain this has been discussed on the forum in the past, but currently, there is no online repository for savefiles, right?

My machine is (slowly) running out of storage space, so I might have to begin deleting the savefiles. It would be nice to have a place to stow them for future interested parties.

I feel your pain; I've got close to 30,000 P-1 save files from the last almost 3 years here in the 40M and 50M ranges. I've been saving them for the same reason but because of the aggressive bounds I used I think it is unlikely there would be value in furthering them.

I don't have the hard math but I think it would be more efficient to take an exponent with lower/mediocre bounds with no save file as a starting point than my aggressively P-1'd exponents with the save file.

[masser]

Originally Posted by petrw1

I don't have the hard math but I think it would be more efficient to take an exponent with lower/mediocre bounds with no save file as a starting point than my aggressively P-1'd exponents with the save file.

Yes, that is true. We could make the case that when the really deep factoring efforts (like those for exponents less than 1M) reach the 40M range, technology will have advanced so far that our current efforts (and savefiles) will be trivial to reproduce.

The savefiles in the 2.6M range are a lot closer to some of the thorough factoring efforts. I don't know enough about those efforts to understand if the savefiles have any value to anyone.

[kruoli]

Originally Posted by masser

My machine is (slowly) running out of storage space, so I might have to begin deleting the savefiles. It would be nice to have a place to stow them for future interested parties.

I have spare storage - before deleting yours, would you mind sending them to me? I could figure out a way to make them publicly availible. How much data are we talking about?

[petrw1]

Originally Posted by kruoli

I have spare storage - before deleting yours, would you mind sending them to me? I could figure out a way to make them publicly availible. How much data are we talking about?

Do you want mine too? I have about 50,000 files of about 5K each.

[kruoli]

Sure, thanks! Maybe this way we can start a central system.