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Old 2021-04-22, 15:26   #166
nordi
 
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Since it is not possible to reserve work for P+1, I'd like to unofficially reserve
  • all already factored exponents from 95k-100k
  • all already factored exponents from 295k-300k
I'll run a first (and if that looks promising, also a second) P+1 curve on them.
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Old 2021-04-22, 16:17   #167
petrw1
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Quote:
Originally Posted by kriesel View Post

[/CODE]Worker window contents from after the comment out of "Pplus1=N/A,1,2,103598543,-1,1000000,30000000,2" and restart, from entry "Pplus1=N/A,1,2,103598543,-1,1000000,30000000,3":
Code:
[Apr 22 00:05] Worker starting
[Apr 22 00:05] Setting affinity to run worker on CPU core #1
[Apr 22 00:05] 
[Apr 22 00:05] P+1 on M103598543 with B1=1000000, B2=30000000

[Apr 22 00:05] All intermediate files bad.  Temporarily abandoning work unit.
[Apr 22 00:05] Optimal P-1 factoring of M103598543 using up to 8192MB of memory.
[Apr 22 00:05] Assuming no factors below 2^76 and 2 primality tests saved if a factor is found.
[Apr 22 00:05] Optimal bounds are B1=796000, B2=34294000
[Apr 22 00:05] Chance of finding a factor is an estimated 4.25%
[Apr 22 04:55] M103598543 stage 1 is 74.88% complete. Time: 813.312 sec.
[Apr 22 05:05] Worker stopped while running needed benchmarks.
[Apr 22 05:13] Benchmarks complete, restarting worker.
[Apr 22 05:13] 
[Apr 22 05:13] P+1 on M103598543 with B1=1000000, B2=30000000
[Apr 22 05:28] M103598543 stage 1 is 2.21% complete. Time: 948.760 sec.
Will abandon the build 1 run and try again with build 2 shortly.
Am I reading this wrong because it appears that:

After the "All ... bad" it switched from P+1 to P-1
Then after Benchmarks it switched back to P+1
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Old 2021-04-22, 16:21   #168
James Heinrich
 
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Quote:
Originally Posted by kriesel View Post
worktodo entry "Pplus1=N/A,1,2,103598543,-1,1000000,30000000,1"
Apparently Prime95 doesn't have sufficient worktodo sanity checks and you're confusing it.
You're specifying Pplus1 as the worktype but setting c to -1 instead of +1.
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Old 2021-04-22, 17:11   #169
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Code:
[Work thread Apr 22 17:45] 
[Work thread Apr 22 17:45] P-1 on M9994027 with B1=2000000, B2=TBD
[Work thread Apr 22 17:45] Setting affinity to run helper thread 1 on CPU core #2
[Work thread Apr 22 17:45] Using FMA3 FFT length 512K, Pass1=256, Pass2=2K, clm=4, 4 threads
[Work thread Apr 22 17:45] Setting affinity to run helper thread 2 on CPU core #3
[Work thread Apr 22 17:45] Setting affinity to run helper thread 3 on CPU core #4
[Comm thread Apr 22 17:45] PrimeNet success code with additional info:
[Comm thread Apr 22 17:45] CPU credit is 4.2951 GHz-days.
[Comm thread Apr 22 17:45] Done communicating with server.
[Work thread Apr 22 17:52] M9994027 stage 1 is 34.65% complete. Time: 449.871 sec.
[Work thread Apr 22 18:00] M9994027 stage 1 is 69.30% complete. Time: 449.951 sec.
[Work thread Apr 22 18:06] M9994027 stage 1 complete. 5771292 transforms. Time: 1298.014 sec.
[Work thread Apr 22 18:06] With trial factoring done to 2^69, optimal B2 is 81*B1 = 162000000.
[Work thread Apr 22 18:06] If no prior P-1, chance of a new factor is 8.48%
[Work thread Apr 22 18:06] D: 1050, relative primes: 2716, stage 2 primes: 8931296, pair%=94.85
[Work thread Apr 22 18:06] Using 11079MB of memory.
[Work thread Apr 22 18:07] Stage 2 init complete. 26786 transforms. Time: 14.315 sec.
[Work thread Apr 22 18:16] M9994027 stage 2 is 20.08% complete. Time: 583.811 sec.
[Work thread Apr 22 18:26] M9994027 stage 2 is 40.59% complete. Time: 591.544 sec.
[Work thread Apr 22 18:38] M9994027 stage 2 is 60.94% complete. Time: 695.522 sec.
[Work thread Apr 22 18:48] M9994027 stage 2 is 80.68% complete. Time: 607.794 sec.
[Work thread Apr 22 18:59] M9994027 stage 2 complete. 9952730 transforms. Time: 3140.027 sec.
[Work thread Apr 22 18:59] Stage 2 GCD complete. Time: 1.496 sec.
[Work thread Apr 22 18:59] P-1 found a factor in stage #2, B1=2000000, B2=162000000.
[Work thread Apr 22 18:59] M9994027 has a factor: 17810607008131132507712387230764284167013708502268550663 (P-1, B1=2000000, B2=162000000)
[Comm thread Apr 22 18:59] Sending result to server: UID: Tha/Z-170, M9994027 has a factor: 17810607008131132507712387230764284167013708502268550663 (P-1, B1=2000000, B2=162000000)
[Comm thread Apr 22 18:59] 
[Work thread Apr 22 18:59] 
[Work thread Apr 22 18:59] P-1 on M9095773 with B1=2000000, B2=TBD
[Work thread Apr 22 18:59] Setting affinity to run helper thread 1 on CPU core #2
[Work thread Apr 22 18:59] Using FMA3 FFT length 480K, Pass1=384, Pass2=1280, clm=4, 4 threads
[Work thread Apr 22 18:59] Setting affinity to run helper thread 2 on CPU core #3
[Work thread Apr 22 18:59] Setting affinity to run helper thread 3 on CPU core #4
[Comm thread Apr 22 18:59] PrimeNet success code with additional info:
[Comm thread Apr 22 18:59] Composite factor 17810607008131132507712387230764284167013708502268550663 = 72324517147464481 * 142671321621631468162223 * 1726062406753801
[Comm thread Apr 22 18:59] Already have factor 72324517147464481 for M9994027
[Comm thread Apr 22 18:59] Already 
[Comm thread Apr 22 18:59] Done communicating with server.
So, mprime 30.5 build 1 found a new factor for an exponent of which three factors were already found before. In the composite factor found two of those three factors were included, the new one of course as well. In the output one previous factor is mentioned correctly, the line that should mention the second previous factor is cut short somehow.
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Old 2021-04-22, 17:13   #170
gLauss
 
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Not sure if it is stupid what I'm doing (it most probably is), but I'm getting stuck for an unreasonable amount of time in the "initializing step" for stage 2 and the CPU is only used a few percent there. This only happens for very small Mersenne numbers.


Code:
Work thread Apr 22 18:28] P+1 on M10069 with B1=10000000, B2=1000000000
[Work thread Apr 22 18:28] Using FMA3 FFT length 512
[Work thread Apr 22 18:34] M10069 stage 1 complete. 43734619 transforms. Time: 353.174 sec.
[Work thread Apr 22 18:34] Stage 1 GCD complete. Time: 0.000 sec.
[Work thread Apr 22 18:40] D: 6930, relative primes: 37104, stage 2 primes: 20838028, pair%=97.80
[Work thread Apr 22 18:40] Using 391MB of memory.
[Work thread Apr 22 18:40] Stage 2 init complete. 119099 transforms. Time: 313.681 sec.
[Work thread Apr 22 18:47] D: 6930, relative primes: 37104, stage 2 primes: 20064499, pair%=96.45
[Work thread Apr 22 18:53] D: 6930, relative primes: 37104, stage 2 primes: 9280428, pair%=95.76
[Work thread Apr 22 18:55] M10069 stage 2 complete. 52013496 transforms. Time: 923.786 sec.
Why did it take 6 minutes to initiliaze after calculating stage 1 GCD? Something strange must be going on here. might be a bug...
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Old 2021-04-22, 17:23   #171
axn
 
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Quote:
Originally Posted by James Heinrich View Post
Apparently Prime95 doesn't have sufficient worktodo sanity checks and you're confusing it.
You're specifying Pplus1 as the worktype but setting c to -1 instead of +1.
Well, someone's confused

c=-1 defines the number being factored (i.e. Mersenne) and not related to the method of factorization.
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Old 2021-04-22, 17:26   #172
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Quote:
Originally Posted by James Heinrich View Post
Apparently Prime95 doesn't have sufficient worktodo sanity checks and you're confusing it.
You're specifying Pplus1 as the worktype but setting c to -1 instead of +1.
ACK! Thanks for spotting and pointing it out. Fixed and restarted.
I've handwritten countless P-1 worktodo lines over the years. Old habits die hard.

edit: Oh, wait, thanks axn, kbnc notation (k b^n + c) for Mp= 2^p - 1 is 1,2,p,-1. Back to as it was.
From whatsnew.txt:
Code:
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"]
(I may be setting a new personal record for attempts per completed factoring try here. Are we having fun yet?!)

Last fiddled with by kriesel on 2021-04-22 at 17:44
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Old 2021-04-22, 17:30   #173
James Heinrich
 
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Quote:
Originally Posted by axn View Post
Well, someone's confused
Hmm, I think I am confused. Sorry.
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Old 2021-04-22, 18:00   #174
ATH
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Quote:
Originally Posted by kriesel View Post
So we must either deduce from the worker history or results file, or open the worktodo file, to see which worktodo line is currently in effect, of nth_run = 1, 2, or 3 for the same exponent/bounds set:
Code:
[Worker #1]
Pplus1=N/A,1,2,exponent,-1,B1,B2,1
Pplus1=N/A,1,2,exponent,-1,B1,B2,2
Pplus1=N/A,1,2,exponent,-1,B1,B2,3
George mentions it making sense to run 2 or maybe 3 runs, but he only mentions nth_run=1 and nth_run=2 for the 2 special starting seeds 2/7 and 6/5, not sure nth_run=3 exists.

Quote:
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.
Regarding the special P+1 seeds, from GMP-ECM Readme:

Quote:
However not all seeds will succeed: only half of the seeds 'x0' work for P+1
(namely those where the Jacobi symbol of x0^2-4 and P is -1.) Unfortunately,
since P is usually not known in advance, there is no way to ensure that this
holds. However, if the seed is chosen randomly, there is a probability of
about 1/2 that it will give a Jacobi symbol of -1 (i.e., the factor P will
be found if P+1 is smooth enough). A rule of thumb is to run 3 times P+1
with different random seeds. The seeds 2/7 and 6/5 have a slightly higher
chance of success than average as they lead to a group order divisible by
6 or 4, respectively. When factoring Fibonacci numbers F_n or Lucas
numbers L_n, using the seed 23/11 ensures that the group order is
divisible by 2n, making other P+1 (and probably P-1) work unnecessary.
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Old 2021-04-22, 18:04   #175
James Heinrich
 
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Quote:
Originally Posted by ATH View Post
not sure nth_run=3 exists.
It does:
Quote:
Originally Posted by Prime95 View Post
Yes, nth_run=3 selects a random starting value.
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Old 2021-04-22, 23:50   #176
storm5510
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The latest version is running fine on my old Xeon with Windows 7 Pro.
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