Prime95 v30.4/30.5/30.6

[Viliam Furik]

Originally Posted by Happy5214

I'm running a P-1 in stage 2, and it's saying it's 100% complete, but it's still running and printing "100% complete" reports at the normal rate. Is there a data issue or is this a problem with the printout that can be safely ignored without compromising the validity of the data until a fix is posted?

This also happened to me a few times with older versions. So far nothing with the new versions. Which one are you using?

[Happy5214]

Originally Posted by Viliam Furik

This also happened to me a few times with older versions. So far nothing with the new versions. Which one are you using?

I was using build 1 of mprime 30.5. I upgraded to build 2 with the same results.

[ixfd64]

Originally Posted by Happy5214

I'm running a P-1 in stage 2, and it's saying it's 100% complete, but it's still running and printing "100% complete" reports at the normal rate. Is there a data issue or is this a problem with the printout that can be safely ignored without compromising the validity of the data until a fix is posted?

I've seen the same issue with stage 1 in earlier versions. Restarting the workers resolves the issue.

[Happy5214]

Originally Posted by ixfd64

I've seen the same issue with stage 1 in earlier versions. Restarting the workers resolves the issue.

That didn't help, nor did restarting mprime completely and resuming from there. Will mprime be able to figure out when this test is actually done, display issues aside, or do I need to restart the test/release the exponent?

[Prime95]

Originally Posted by Happy5214

That didn't help, nor did restarting mprime completely and resuming from there. Will mprime be able to figure out when this test is actually done, display issues aside, or do I need to restart the test/release the exponent?

Can you send the save file and worktodo.txt? Thanks.

[Happy5214]

Originally Posted by Prime95

Can you send the save file and worktodo.txt? Thanks.

I don't have them anymore, because the assignment already finished and got uploaded to PrimeNet (no factor found). You got the PRP test (it was 103482079, for future reference). I'll send the files if/when it happens again with another exponent. Sorry for not being helpful.

[Prime95]

Prime95 version 30.6 build 2 is available.

I consider the new features to be lightly tested. No need to upgrade unless you are doing ECM or care to try out the new P+1 factoring work.

You could be the first to find a new factor using P+1. I've tried about 10 times without success.

Think of P+1 as a special fast ECM curve -- same chances of success, several times faster than ECM, but you only get to do it once. My thoughts are to choose B1 well above the current B1's being handed out by the server for ECM. For the few exponents I tried in the 4.7M area, ECM is presently being done at B1=50K, I chose P+1 with B1=1M.

From whatsnew.txt:

1) P+1 factoring.  A worktodo.txt entry looks like this:
	Pplus1=k,b,n,c,B1,B2,nth_run[,how_far_factored][,"known_factors"]
   Unlike P-1, the fact that factors of Mersenne numbers is 1 mod 2p is of no value.
   Thus, P-1 is vastly more effective at finding factors.  A P+1 run is about as
   valuable as running one ECM curve.  P+1 stage 1 is 50% slower than P-1 stage 1
   but several times faster than ECM stage 1.  P+1 stage 2 is a little faster than
   P-1 stage 2 which in turn is a little faster than ECM stage 2.
   Unlike P-1, P+1 has only a 50% chance of finding a factor if factor+1 is B1/B2 smooth.
   Thus, it makes sense to do 1 or 2 (maybe 3) runs.  That is what the nth_run argument is for.
   There are two special starting values for P+1 that have a slightly higher chance of
   finding a factor.  These special starting values correspond to nth_run=1 and nth_run=2.
   Like P-1, if how_far_factored is specified, prime95 will ignore B2 and calculate the
   best B2 value for the given B1.
2) Faster ECM stage 1 when factoring exponents near the limit of an FFT size.
3) Gwnum library new functions give a programmer more tools to reduce normalized adds.
   A tutorial.txt file is now available to help a programmer use the gwnum library.

Download links:

Before downloading, make sure prime.spl is uploaded to the server. There is a bug reading spool files created by previous versions.

Windows 64-bit: https://mersenne.org/ftp_root/gimps/p95v306b2.win64.zip
Linux 64-bit: https://mersenne.org/ftp_root/gimps/...linux64.tar.gz

[masser]

George, this is excellent. Thank you!

Would it be possible to add another value to nth_flag, like -1, that signals to the code to run each of the (2, 3?) starting seeds? Also, it's not clear how to make the code do 3 distinct runs on the same number with the same bounds.

[Prime95]

Originally Posted by masser

George, this is excellent. Thank you!

Would it be possible to add another value to nth_flag, like -1, that signals to the code to run each of the (2, 3?) starting seeds? Also, it's not clear how to make the code do 3 distinct runs on the same number with the same bounds.

Yes, nth_run=3 selects a random starting value.

Given the massive number of exponents in need of P+1, I recommend not doing two P+1 runs on the same exponent. That said, do whatever you find fun.

[axn]

Is the server set up to handle P+1 result submissions (both "no factor" as well as "factor found")?

Is mersenne.ca?

[James Heinrich]

Originally Posted by axn

Is the server set up to handle P+1 result submissions (both "no factor" as well as "factor found")?
Is mersenne.ca?

Yes, and yes. Largely untested in both cases of course, so let me know if you find something not working as it should.