P-1 coordination thread - discussion

[hhh]

Won't they still be useful for secondpass, though?

Yes, but the whole purpose of P-1 is to save tests at a last stand, isn't it? H.

[Max Dettweiler]

Yes, but the whole purpose of P-1 is to save tests at a last stand, isn't it? H.

I would think that even if the number has been tested once, a factor for that number can still save us from having to do the secondpass test.

[hhh]

I would think that even if the number has been tested once, a factor for that number can still save us from having to do the secondpass test.

That's right. Yet, it will happen only in a few years, and by that time, there is a good chance that a prime will be found or that sieving would have found that factor. And then, P-1 is not superfast. By the time it takes to find this factor, one could have done this one LLR test; but not two.

So, if one would want to look for factors of Doublecheck numbers, one would do that right before doublecheck hits them, and then again, one would not do it at all, because you are better off with LLR directly.

I hope I look not too wise-assed now... H.

[balachmar]

Does mprime have to do the second pass tests as well, because on this machine I have it running for a while, but I didn't change the memory setting, so it doesn't do second pass tests. How bad is that?
On my other machine, I actually opted for a range that seems to be passed by PRP. But then it will be finished by now, so I will send the results in this evening.

[hhh]

Does mprime have to do the second pass tests as well, because on this machine I have it running for a while, but I didn't change the memory setting, so it doesn't do second pass tests. How bad is that?
On my other machine, I actually opted for a range that seems to be passed by PRP. But then it will be finished by now, so I will send the results in this evening.

Stage2 is needed to find factors. In your mprime directory, look for a bunch of files called (one letter)(long number), I hope you get what I mean. it could be something like
z5123875 or
f1329834

if they are there, you probably can just put in the stuff for worktodo.txt again, change your memory settings, and it will start to do all the stage2 for the tests. If that fails, it is proably better to drop that range and to do another one with larger memory settings, rather than redoing all the stage 1 work.

H.

[balachmar]

OK, thanks for the clarification. I know what you mean with the files.
I will copy the lot to another machine, since this machine is doing some other work at the moment. I hope that the other machine will be able to finish it. OK, I first tried to get it to run on this machine and that works.
So I will complete it normally.

[balachmar]

I'll post here not to trash the other thread, but my range resulted in one factor, not two!
14920000 14921000 balachmar 1 [complete]