Prime95 v30.4/30.5/30.6 - Page 43

James Heinrich · 2021-10-02, 20:16

Quote:

Originally Posted by tha

Can we download and test that version? Or should we wait for more wrinkles to be ironed out?

It's still George's development version, not yet ready for testing.

kriesel · 2021-10-05, 13:47

For M58793159, 3M fft length may be a bit too aggressive in prime95 v30.6b4; got roundoff error 0.4375 >0.4 at iteration 292709 on Celeron G1840.

kruoli · 2021-10-10, 19:07

v30.6b4: If stage 1 GCD is disabled, the optimal B2 seems to always be calculated as 100*B1. The worktodo had another value for B2 and the usual multiplicator for same-sized exponents when stage 1 GCD is enabled is way lower.

Prime95 · 2021-10-10, 20:02

Quote:

Originally Posted by kruoli

v30.6b4: If stage 1 GCD is disabled, the optimal B2 seems to always be calculated as 100*B1. The worktodo had another value for B2 and the usual multiplicator for same-sized exponents when stage 1 GCD is enabled is way lower.

ECM? Does this happen in 30.7? If so, what is the worktodo.txt entry?

Prime95 · 2021-10-10, 20:04

Quote:

Originally Posted by kriesel

For M58793159, 3M fft length may be a bit too aggressive in prime95 v30.6b4; got roundoff error 0.4375 >0.4 at iteration 292709 on Celeron G1840.

0.4375 is not that scary (to me). However, you aren't near the 3M FFT limit. Please advise if more (and worse) errors occur as you move higher.

James Heinrich · 2021-10-10, 20:10

Quote:

Originally Posted by Prime95

ECM? Does this happen in 30.7? If so, what is the worktodo.txt entry?

Maybe when there's a new version released, George should post in the sticky thread of the previous version to let us lurkers know there's a new version on offer. I for one almost never browse the forum to see what's new, I just checked my watched threads when I get emailed.
https://www.mersenneforum.org/showthread.php?t=27180

kruoli · 2021-10-10, 20:31

Quote:

Originally Posted by Prime95

ECM? Does this happen in 30.7? If so, what is the worktodo.txt entry?

This was with P-1, e.g. Pminus1=1,2,27318307,-1,1200000,40500000,74. I'll retry with 30.7 soon. If you look at the exponent page of M27318307, you'll see I have two results there (mprime was killed by the kernel and the worktodo.txt content was still the same as of two days prior, I did not notice that before restarting and duplicated work that way, I thought WellBehavedWork would write the file more frequently; I digress). The first was before I added the stage 1 skip, the second one after, so it's definitely the same worktodo entry.

Prime95 · 2021-10-10, 21:17

Quote:

Originally Posted by kruoli

This was with P-1, e.g. Pminus1=1,2,27318307,-1,1200000,40500000,74. I'll retry with 30.7 soon. If you look at the exponent page of M27318307, you'll see I have two results there (mprime was killed by the kernel and the worktodo.txt content was still the same as of two days prior, I did not notice that before restarting and duplicated work that way, I thought WellBehavedWork would write the file more frequently; I digress). The first was before I added the stage 1 skip, the second one after, so it's definitely the same worktodo entry.

FYI: 30.7 always skips stage 1 GCD for P-1 (you'll get it for free during stage 2 init)
FYI2: Brent-Suyama is no more.

Do you keep old save file around for possibly later increasing B2? Could this bug have something to do with picking up an old save file and increasing its bounds rather than a consequence of stage1gcd=0?

kruoli · 2021-10-10, 21:21

Ah, okay. So I cannot proceed to stage 2 when a factor would be found in stage 1? (Yes, this is not necessary for most use cases, just asking.)

The problem I described earlier does therefore not occur in 30.7, I just tested it, sorry for the tumult.

kruoli · 2021-10-10, 21:24

Quote:

Originally Posted by Prime95

FYI2: Brent-Suyama is no more.

Sometimes things have to go.

I think you mentioned that earlier.
Edit: I had the setting still active and the program wrote that it had used Brent-Suyama to the JSON file, maybe this should be ignored and not written to the result file? I'll delete the setting nonetheless, but I hope I do not forget to do this for all of my machines...

Quote:

Originally Posted by Prime95

Do you keep old save file around for possibly later increasing B2? Could this bug have something to do with picking up an old save file and increasing its bounds rather than a consequence of stage1gcd=0?

That's might be it! Because of running all jobs a second time (unintentionally), they were run two times with the same B1, the second time only resumed. I had not watched the machine for a while, otherwise I should have seen this. Shall I try this with 30.7, too?

Prime95 · 2021-10-10, 23:33

Quote:

Originally Posted by kruoli

Ah, okay. So I cannot proceed to stage 2 when a factor would be found in stage 1? (Yes, this is not necessary for most use cases, just asking.).

It can be done. Read undoc.txt regarding Stage1GCD setting.

Quote:

Originally Posted by kruoli

That's might be it! Because of running all jobs a second time (unintentionally), they were run two times with the same B1, the second time only resumed. I had not watched the machine for a while, otherwise I should have seen this. Shall I try this with 30.7, too?

If you can reproduce a problem, I'll investigate a fix.

2021-10-05, 13:47	#464
kriesel "TF79LL86GIMPS96gpu17" Mar 2017 US midwest 2·29·127 Posts	For M58793159, 3M fft length may be a bit too aggressive in prime95 v30.6b4; got roundoff error 0.4375 >0.4 at iteration 292709 on Celeron G1840.

2021-10-10, 19:07	#465
kruoli "Oliver" Sep 2017 Porta Westfalica, DE 1,327 Posts	v30.6b4: If stage 1 GCD is disabled, the optimal B2 seems to always be calculated as 100*B1. The worktodo had another value for B2 and the usual multiplicator for same-sized exponents when stage 1 GCD is enabled is way lower.

2021-10-10, 21:21	#471
kruoli "Oliver" Sep 2017 Porta Westfalica, DE 1,327 Posts	Ah, okay. So I cannot proceed to stage 2 when a factor would be found in stage 1? (Yes, this is not necessary for most use cases, just asking.) The problem I described earlier does therefore not occur in 30.7, I just tested it, sorry for the tumult.