P-1 coordination thread - discussion

[balachmar]

I can not see the factor in the stats. Is the factor big? Then post it here.

Too bad I only read this now. I don't think I have the values of the factor anymore...
And as far as I know the submission page accepted the factor...
mm strange...
Anyway, I'm getting a bit fed up with P-1 did a few like 40 lines of work and still no result... (As in points for the team and tests saved...)

[[DPC]Frentik]

Sorry if asked before but these are the steps I performed to do P-1 factoring and I want to make sure it's done properly

- Created account at www.seventeenorbust.com and joined my team there.
- downloaded latest prime95 version from www.mersenne.org
- reserved a range in the appropriate thread and saved it in the prime95 folder
- started prime95 and choose "join GIMPS" (then I had to fill in a username/email etc but i assume this is only used if you do mersenne prime finding? <- insecure on this part)
-stopped prime95, added the results.txt=fact.txt to the prime.ini file and restarted prime95.

It's running now and since its working on the first value from the worktodo.ini file I assume this part is correct so far.

Now when I find a factor I only have to submit it at www.seventeenorbust.com/sieve? And when the range is done, I'll post it in the coordination thread.

[Joe O]

If the factor is larger than 2^64 then you have to submit it here.

[Joh14vers6]

I switched over from prime v25.6 to v25.7.
Since I switched over I see an extra text at the result.txt.
With 25.6 I had results like:

[Fri Oct 10 20:25:04 2008]
21181*2^15854852+1 completed P-1, B1=130000, B2=2200000, Wd1: 9A15E8A8

And now with 25.7 I mostly get results like:

[Tue Oct 14 22:45:12 2008]
55459*2^16041334+1 completed P-1, B1=130000, B2=2200000, E=6, Wd1: 9F09E1E8

What does E=6 mean?

[opyrt]

I switched over from prime v25.6 to v25.7.
Since I switched over I see an extra text at the result.txt.
With 25.6 I had results like:

[Fri Oct 10 20:25:04 2008]
21181*2^15854852+1 completed P-1, B1=130000, B2=2200000, Wd1: 9A15E8A8

And now with 25.7 I mostly get results like:

[Tue Oct 14 22:45:12 2008]
55459*2^16041334+1 completed P-1, B1=130000, B2=2200000, E=6, Wd1: 9F09E1E8

What does E=6 mean?

I'm getting the same thing on my 32 bit client, but not on the 64 bit client.

Edit: I now see that this has been answered on mersenneforum: http://www.mersenneforum.org/showthread.php?t=10902

[Joh14vers6]

Today I found the factor:
P-1 found a factor in stage #2, B1=130000, B2=2200000.
21181*2^16496492+1 has a factor: 13825033371936547

But I will not get any credit for it because user 13796 (PrimeGrid) already found this factor.
I found that out here: http://www.seventeenorbust.com/sieve/results.txt.bz2
I searched for more tests with already found factors in my worktodo.txt and found another two already found factors by PrimeGrid. So I deleted them from the worktodo.txt.

How can I prevent PrimeGrid finding my factors first?

[shauge]

It is always annoying when not getting credit for a factor found. There is of course no way to prevent sieving finding factors in your factoring range. It is only possible check for found factors before starting factoring. The factor you post is 13.8P which is in a sieve range PrimeGrid did a some time ago and when I look in the "worktodo_16000000_16500000.zip" posted in the "P1 coordination thread", the test you post have been excluded. You should use an updated worktodo file.

[Joe O]

How can I prevent PrimeGrid finding my factors first?

By checking your worktodo.txt against results.txt on a daily basis and removing k n pairs from your worktodo.txt that have already been factored and posted in results.txt.

Edit:

You should use an updated worktodo file.

Thanks shauge. I wrote my answer before seeing your post. I did not consider that Joh14vers6 would have used an obsolete worktoto file. Actually, even my advice to check it daily would not always work. You are correct in saying that there is no way to prevent this from happening.