P-1 thread discussions

My new code was doing about a curve an hour at 128 MB and what you call a 2.0 setting. This translated to B1=40000 and B2=340000. I'm not sure how long sbfactor would take on my 2.1 GHz P4.

If there is interest I can package up this executable for you guys to test. There are limitations: P4/A64 only, Windows only, different user interface. It will take quite a while before the gwum library is ready for linking into sbfactor.

P.S. I'm amazed at how deep you guys have sieved. I'm used to having a 3 to 5% chance of a P-1 hit on GIMPS and here I'm getting less than a 1% chance!

when more memory is used the chances improv greatly. Perhaps you might have some input on the optimal bounds selecting. I am curious if the likelyness of a factor being found is just from experiments or from theory. perhaps using the results file we could see exactly how many smooth factors exist for each range. Perhaps that would be a bettr way or determineing the likelyness of finding a factor instead of theory that is often unreliable when dealing with extreme circumstances as we have here. This isn't a question for prime95 this is for anyone with input. How do the current optimal bounds selectors work?

Quote:

---

Originally posted by prime95
If there is interest I can package up this executable for you guys to test.

---

That would be wonderful. May be I'm wrong, but it sounds as if it's much faster. Thanks in advance.

Here is the Windows SSE2-only pre-beta P-1 factorer. You can get it from ftp://mersenne.org/gimps/sobpm1.zip

There is a text file you'll need to read before using it.

Please try a few known factors before giving it a go. This is only lightly tested. Bug reports are most welcome.

My PC requies mfc70d.dll file to run the client (and probably some others).

EDIT: Found the file here. I'm posting the link in case somebody else requires the file (download at your own risk). It's really scarce.

By the way, what is 1 in Pfactor=k,2,n,1,49,0? Does it refer to the +1 in k*2^n+1, or is it something else?

The zip file now contains two executables, a debug build and a release build.

The first four arguments in "Pfactor=k,2,n,1" are k,b,n,c in k*b^n+c.

First (very early) comments.

- Thanks for the new client beta. I'm sure we'll soon have a solid and efficient client soon.

- The client seems to be much faster. The estimated completion time for a k/n=6m pair with B1=30000, B2=270000 is ~60 min , whereas it took ~100 min for B1=10000, B2=100000 with the original client. PS: It might take longer. The expected completion at status window is increasing. Still, the new client looks faster.

- Where are the factors written? If they're written to results.txt file like in Mersenne project, could you please use another name for the file? (fact.txt would be very nice). We also have a results.txt file which contains our factors for p>25T.

- I first tried with:
Pfactor=24737,2,1008463,1,49,0
Pfactor=27653,2,5992989,1,49,0
at worktodo.ini. The client simply skips the first one and starts the second one. We do not need to factor n=1m files, but it might signal a bug.


- Is it possible to use numbers like 1.4 as the last input in Pfactor=k,2,n,1,49,0. I tried some alternatives. But the client seems to skip the k/n pair (and delete it from the worktodo.ini) in case there is an input with decimal there.


More will come later.

I've run Pfactor=27653,2,5992989,1,49,0 to 43% on stage 1. Stopped the client, added Pminus1=21181,2,5777180,1,10000,100000 to the first line of worktodo.ini (pushing Pfactor=27653,2,5992989,1,49,0 to the second line).

Here's what status looks like at that stage.

Try putting this line in prime.ini: "results.txt=fact.txt"
That feature should rename the output file.


The Pfactor=k,2,1000000,1,49,1 not getting executed is simply due to the program concluding that P-1 doesn't make sense for such a small number that has been factored to 2^49. I'll look at outputting a line rather than silently skipping the worktodo entry.

It is a known limitation that Pminus1= lines are not estimated properly by Test/Status.

well this should soon help the P-1 effort aintaine speed with the PRP effort, No? Unless of course some of these optimizations could be transcribed over to the PRP too. I do remember hearing that muchg of the code between the two was very similar.

Thanks for quick answers George. I'll do some more tests in the following days and post here if I encounter something interesting.

It took 40 mins to find:

[Tue Jun 08 04:13:00 2004]
P-1 found a factor in stage #2, B1=10000, B2=100000.
21181*2^5777180+1 has a factor: 407337342926141

IIRC, it took 60 mins for SBFactor to finish the same k/n pair with B1=10000, B2=65000 on the same machine. So, significantly faster.


Notes:

- We need a program that will create the input lines for worktodo.ini when the user enters nmin and nmax.

- We need a second program that enables communication between SOBPM1 output and sieve submission format.

Quote:

---

Originally posted by Keroberts1
Unless of course some of these optimizations could be transcribed over to the PRP too. I do remember hearing that much of the code between the two was very similar.

---

These optimizations will help PRP too. However, I need to put the new code through a lot more testing before that happens. If I introduce a bug in P-1 factoring, the worst that happens is you miss a factor. A bug in PRPing could miss a prime!

great to hear :cheers:

I've created a work queue from the P-1 factors we've found so far.

Parameters are:
- 2^49 < p < 2^64
- 4000000 < n < 6365000
- factors found through sieve are excluded
- duplicates are included (there's only one such case)

There are 212 k/n pairs of such.

The client did not factor anything below 4926821 for the setting 0 (two times PRP). Pfactor=10223,2,4926821,1,49,0 is the first work accepted by the client for 160 MB RAM allocation on a PIV-1700.

So, there's a set of 140 k/n pairs available for testing.


I started testing them, but the whole set is too much for me.

I can post some blocks of k/n pairs (in Pfactor=k,2,n,1,49,0 format) if anyone is interested in testing the client.


BTW:

- putting results.txt=fact.txt line in prime.ini seems to work

- as far as the times PRP setting is concerned, it's not only the decimals that do not work. Integers like 3, 4, etc. does not work either (not that they'll be used).

Quote:

---

Originally posted by Nuri
I can post some blocks of k/n pairs (in Pfactor=k,2,n,1,49,0 format) if anyone is interested in testing the client.

---

*Interested* ;)

Sure, I'll post some when I go home tonight.

First, my test results so far.

The client skipped all of the 72 tests below n=4926821.

I tested 53 k/n pairs from 4926821 to 5673943 (both included).

As far as I can see, the results can be grouped into two.

1. Tests below 548000:
This area is tricky. The client
- skipped 23 tests,
- found the factors for 4 tests, and
- could not find factors for 3 tests.

2. Tests above 5480000:
The client found all 23 factors.

-----

Please find below the detailed results. The format for the results below is:

The factor we found by P-1
Test client worktodo.ini input line
Test client result (or my comment if the test as skipped by the client)

1642178249068589 | 10223*2^4926821+1
Pfactor=10223,2,4926821,1,49,0
10223*2^4926821+1 completed P-1, B1=20000, B2=190000, WZ1: 7FA28ADC

298757939128829629 | 5359*2^4932486+1
Pfactor=5359,2,4932486,1,49,0
5359*2^4932486+1 has a factor: 298757939128829629

3022753468710323 | 5359*2^4985022+1
Pfactor=5359,2,4985022,1,49,0
5359*2^4985022+1 has a factor: 3022753468710323

7088096697598673 | 55459*2^5101474+1
Pfactor=55459,2,5101474,1,49,0
the client skipped this test

232926929846780599 | 4847*2^5102007+1
Pfactor=4847,2,5102007,1,49,0
4847*2^5102007+1 completed P-1, B1=20000, B2=190000, WZ1: 840FF103

1616859400969889249 | 10223*2^5107709+1
Pfactor=10223,2,5107709,1,49,0
the client skipped this test

1478855049607009 | 22699*2^5120614+1
Pfactor=22699,2,5120614,1,49,0
the client skipped this test

589241016128671903 | 4847*2^5121303+1
Pfactor=4847,2,5121303,1,49,0
4847*2^5121303+1 has a factor: 589241016128671903

762098342145967 | 21181*2^5122772+1
Pfactor=21181,2,5122772,1,49,0
the client skipped this test

17915702690728657 | 55459*2^5123038+1
Pfactor=55459,2,5123038,1,49,0
the client skipped this test

968947423096291 | 5359*2^5123766+1
Pfactor=5359,2,5123766,1,49,0
5359*2^5123766+1 has a factor: 968947423096291

1250773527381738389 | 24737*2^5124367+1
Pfactor=24737,2,5124367,1,49,0
the client skipped this test

3890219409956567 | 55459*2^5124826+1
Pfactor=55459,2,5124826,1,49,0
the client skipped this test

3448105179147583 | 33661*2^5205048+1
Pfactor=33661,2,5205048,1,49,0
the client skipped this test

1890202050860579 | 4847*2^5205111+1
Pfactor=4847,2,5205111,1,49,0
4847*2^5205111+1 completed P-1, B1=25000, B2=212500, WZ1: 86AB56F3

3892606265176382447 | 28433*2^5245033+1
Pfactor=28433,2,5245033,1,49,0
the client skipped this test

1006791864086011 | 22699*2^5301910+1
Pfactor=22699,2,5301910,1,49,0
the client skipped this test

2777060416448011 | 24737*2^5303767+1
Pfactor=24737,2,5303767,1,49,0
the client skipped this test

1120067536731277 | 21181*2^5304212+1
Pfactor=21181,2,5304212,1,49,0
the client skipped this test

5346081339902940419 | 28433*2^5307673+1
Pfactor=28433,2,5307673,1,49,0
the client skipped this test

2498287469935123 | 10223*2^5308541+1
Pfactor=10223,2,5308541,1,49,0
the client skipped this test

888917795346331 | 55459*2^5317534+1
Pfactor=55459,2,5317534,1,49,0
the client skipped this test

798402259594481 | 24737*2^5318911+1
Pfactor=24737,2,5318911,1,49,0
the client skipped this test

88310736740738929 | 24737*2^5320951+1
Pfactor=24737,2,5320951,1,49,0
the client skipped this test

340365599269738517 | 19249*2^5322218+1
Pfactor=19249,2,5322218,1,49,0
the client skipped this test

216324352986783397 | 10223*2^5326121+1
Pfactor=10223,2,5326121,1,49,0
the client skipped this test

333344685330888353 | 19249*2^5326862+1
Pfactor=19249,2,5326862,1,49,0
the client skipped this test

2271657032710253 | 21181*2^5329652+1
Pfactor=21181,2,5329652,1,49,0
the client skipped this test

2711637975518893 | 10223*2^5330405+1
Pfactor=10223,2,5330405,1,49,0
the client skipped this test

1298422551990943 | 55459*2^5336866+1
Pfactor=55459,2,5336866,1,49,0
the client skipped this test

1702062035206919 | 27653*2^5480061+1
Pfactor=27653,2,5480061,1,49,0
27653*2^5480061+1 has a factor: 1702062035206919

797778229476377 | 22699*2^5480470+1
Pfactor=22699,2,5480470,1,49,0
22699*2^5480470+1 has a factor: 797778229476377

783357760490677 | 55459*2^5481334+1
Pfactor=55459,2,5481334,1,49,0
55459*2^5481334+1 has a factor: 783357760490677

2490175855835303 | 4847*2^5481927+1
Pfactor=4847,2,5481927,1,49,0
4847*2^5481927+1 has a factor: 2490175855835303

384493174147192573 | 67607*2^5484267+1
Pfactor=67607,2,5484267,1,49,0
67607*2^5484267+1 has a factor: 384493174147192573

17227108922055551 | 19249*2^5486126+1
Pfactor=19249,2,5486126,1,49,0
19249*2^5486126+1 has a factor: 17227108922055551

19030971212858639 | 19249*2^5491598+1
Pfactor=19249,2,5491598,1,49,0
19249*2^5491598+1 has a factor: 19030971212858639

103596681290541143 | 33661*2^5550432+1
Pfactor=33661,2,5550432,1,49,0
33661*2^5550432+1 has a factor: 103596681290541143

2186703185472067 | 10223*2^5595929+1
Pfactor=10223,2,5595929,1,49,0
10223*2^5595929+1 has a factor: 2186703185472067

62447276586432949 | 28433*2^5598025+1
Pfactor=28433,2,5598025,1,49,0
28433*2^5598025+1 has a factor: 62447276586432949

412016110183932931 | 22699*2^5602654+1
Pfactor=22699,2,5602654,1,49,0
22699*2^5602654+1 has a factor: 412016110183932931

315608255140912871 | 24737*2^5606887+1
Pfactor=24737,2,5606887,1,49,0
24737*2^5606887+1 has a factor: 315608255140912871

46736570240095201 | 24737*2^5611207+1
Pfactor=24737,2,5611207,1,49,0
24737*2^5611207+1 has a factor: 46736570240095201

2272180866513823 | 21181*2^5616452+1
Pfactor=21181,2,5616452,1,49,0
21181*2^5616452+1 has a factor: 2272180866513823

5013169446620738903 | 4847*2^5621151+1
Pfactor=4847,2,5621151,1,49,0
4847*2^5621151+1 has a factor: 5013169446620738903

1042382178159409 | 21181*2^5621468+1
Pfactor=21181,2,5621468,1,49,0
21181*2^5621468+1 has a factor: 1042382178159409

1328735974435881607 | 22699*2^5627854+1
Pfactor=22699,2,5627854,1,49,0
22699*2^5627854+1 has a factor: 1328735974435881607

208629015721752851 | 10223*2^5629241+1
Pfactor=10223,2,5629241,1,49,0
10223*2^5629241+1 has a factor: 208629015721752851

28195479692754961 | 67607*2^5635211+1
Pfactor=67607,2,5635211,1,49,0
67607*2^5635211+1 has a factor: 28195479692754961

22851488069566757 | 5359*2^5646262+1
Pfactor=5359,2,5646262,1,49,0
5359*2^5646262+1 has a factor: 22851488069566757

11974770314169263 | 21181*2^5648732+1
Pfactor=21181,2,5648732,1,49,0
21181*2^5648732+1 has a factor: 11974770314169263

6051228394673221 | 24737*2^5666431+1
Pfactor=24737,2,5666431,1,49,0
24737*2^5666431+1 has a factor: 6051228394673221

9811491219057001 | 24737*2^5673943+1
Pfactor=24737,2,5673943,1,49,0
24737*2^5673943+1 has a factor: 9811491219057001

Please find below the input line for the 72 tests that the client skipped at the first place. In case somebody else wants to give a try with different hardware and RAM settings (mine was 160 MB).

Pfactor=19249,2,4003538,1,49,0
Pfactor=10223,2,4005017,1,49,0
Pfactor=5359,2,4006302,1,49,0
Pfactor=67607,2,4022171,1,49,0
Pfactor=28433,2,4027873,1,49,0
Pfactor=10223,2,4029221,1,49,0
Pfactor=5359,2,4038382,1,49,0
Pfactor=55459,2,4040698,1,49,0
Pfactor=24737,2,4054831,1,49,0
Pfactor=5359,2,4055790,1,49,0
Pfactor=33661,2,4064496,1,49,0
Pfactor=21181,2,4065980,1,49,0
Pfactor=55459,2,4069738,1,49,0
Pfactor=10223,2,4073981,1,49,0
Pfactor=67607,2,4091211,1,49,0
Pfactor=28433,2,4091425,1,49,0
Pfactor=21181,2,4108364,1,49,0
Pfactor=27653,2,4114797,1,49,0
Pfactor=4847,2,4122567,1,49,0
Pfactor=55459,2,4132918,1,49,0
Pfactor=21181,2,4134692,1,49,0
Pfactor=24737,2,4149607,1,49,0
Pfactor=67607,2,4150107,1,49,0
Pfactor=28433,2,4150417,1,49,0
Pfactor=55459,2,4151566,1,49,0
Pfactor=4847,2,4155831,1,49,0
Pfactor=21181,2,4156100,1,49,0
Pfactor=21181,2,4162724,1,49,0
Pfactor=5359,2,4164942,1,49,0
Pfactor=5359,2,4169766,1,49,0
Pfactor=10223,2,4172189,1,49,0
Pfactor=33661,2,4172496,1,49,0
Pfactor=55459,2,4173886,1,49,0
Pfactor=4847,2,4177407,1,49,0
Pfactor=27653,2,4184205,1,49,0
Pfactor=33661,2,4188096,1,49,0
Pfactor=22699,2,4252294,1,49,0
Pfactor=28433,2,4300225,1,49,0
Pfactor=33661,2,4447032,1,49,0
Pfactor=10223,2,4530041,1,49,0
Pfactor=33661,2,4532712,1,49,0
Pfactor=55459,2,4534834,1,49,0
Pfactor=27653,2,4538445,1,49,0
Pfactor=33661,2,4541544,1,49,0
Pfactor=21181,2,4543700,1,49,0
Pfactor=5359,2,4544686,1,49,0
Pfactor=10223,2,4545869,1,49,0
Pfactor=4847,2,4546887,1,49,0
Pfactor=28433,2,4546993,1,49,0
Pfactor=33661,2,4570008,1,49,0
Pfactor=5359,2,4571326,1,49,0
Pfactor=10223,2,4571705,1,49,0
Pfactor=27653,2,4571709,1,49,0
Pfactor=55459,2,4574206,1,49,0
Pfactor=28433,2,4620625,1,49,0
Pfactor=22699,2,4621942,1,49,0
Pfactor=21181,2,4647212,1,49,0
Pfactor=10223,2,4753865,1,49,0
Pfactor=21181,2,4754228,1,49,0
Pfactor=10223,2,4755461,1,49,0
Pfactor=33661,2,4761600,1,49,0
Pfactor=28433,2,4762105,1,49,0
Pfactor=5359,2,4765870,1,49,0
Pfactor=27653,2,4766289,1,49,0
Pfactor=10223,2,4780349,1,49,0
Pfactor=10223,2,4780397,1,49,0
Pfactor=33661,2,4780752,1,49,0
Pfactor=4847,2,4820583,1,49,0
Pfactor=10223,2,4822349,1,49,0
Pfactor=4847,2,4830063,1,49,0
Pfactor=10223,2,4832441,1,49,0
Pfactor=21181,2,4922300,1,49,0

Please find below the the input line for the remaining 87 tests. I'm not planning further tests for the time being, so feel free to grab anything you like.

Pfactor=33661,2,5674272,1,49,0
Pfactor=27653,2,5690625,1,49,0
Pfactor=24737,2,5705071,1,49,0
Pfactor=27653,2,5705673,1,49,0
Pfactor=4847,2,5707551,1,49,0
Pfactor=24737,2,5709871,1,49,0
Pfactor=27653,2,5713017,1,49,0
Pfactor=55459,2,5720278,1,49,0
Pfactor=67607,2,5726411,1,49,0
Pfactor=21181,2,5726972,1,49,0
Pfactor=55459,2,5730718,1,49,0
Pfactor=10223,2,5732837,1,49,0
Pfactor=10223,2,5733485,1,49,0
Pfactor=27653,2,5737929,1,49,0
Pfactor=28433,2,5741185,1,49,0
Pfactor=24737,2,5754367,1,49,0
Pfactor=4847,2,5754687,1,49,0
Pfactor=55459,2,5758438,1,49,0
Pfactor=33661,2,5767488,1,49,0
Pfactor=28433,2,5768017,1,49,0
Pfactor=10223,2,5774585,1,49,0
Pfactor=10223,2,5781065,1,49,0
Pfactor=19249,2,5794718,1,49,0
Pfactor=4847,2,5801991,1,49,0
Pfactor=21181,2,5804804,1,49,0
Pfactor=55459,2,5843506,1,49,0
Pfactor=4847,2,5846367,1,49,0
Pfactor=55459,2,5868118,1,49,0
Pfactor=10223,2,5869769,1,49,0
Pfactor=22699,2,5874598,1,49,0
Pfactor=24737,2,5880343,1,49,0
Pfactor=10223,2,5884637,1,49,0
Pfactor=27653,2,5888841,1,49,0
Pfactor=24737,2,5951647,1,49,0
Pfactor=33661,2,5963328,1,49,0
Pfactor=67607,2,5965947,1,49,0
Pfactor=22699,2,5989654,1,49,0
Pfactor=27653,2,5992989,1,49,0
Pfactor=27653,2,5998713,1,49,0
Pfactor=4847,2,6001023,1,49,0
Pfactor=24737,2,6003031,1,49,0
Pfactor=55459,2,6004246,1,49,0
Pfactor=21181,2,6025868,1,49,0
Pfactor=33661,2,6027912,1,49,0
Pfactor=55459,2,6032314,1,49,0
Pfactor=24737,2,6053911,1,49,0
Pfactor=33661,2,6055008,1,49,0
Pfactor=55459,2,6077758,1,49,0
Pfactor=24737,2,6079111,1,49,0
Pfactor=21181,2,6094532,1,49,0
Pfactor=24737,2,6094663,1,49,0
Pfactor=33661,2,6095592,1,49,0
Pfactor=10223,2,6096761,1,49,0
Pfactor=21181,2,6103172,1,49,0
Pfactor=24737,2,6104311,1,49,0
Pfactor=24737,2,6107023,1,49,0
Pfactor=28433,2,6107737,1,49,0
Pfactor=27653,2,6111897,1,49,0
Pfactor=10223,2,6113177,1,49,0
Pfactor=28433,2,6118297,1,49,0
Pfactor=4847,2,6161007,1,49,0
Pfactor=24737,2,6161263,1,49,0
Pfactor=24737,2,6162487,1,49,0
Pfactor=10223,2,6165605,1,49,0
Pfactor=21181,2,6167900,1,49,0
Pfactor=28433,2,6170953,1,49,0
Pfactor=55459,2,6172258,1,49,0
Pfactor=33661,2,6173496,1,49,0
Pfactor=4847,2,6174351,1,49,0
Pfactor=28433,2,6180505,1,49,0
Pfactor=28433,2,6181297,1,49,0
Pfactor=10223,2,6182117,1,49,0
Pfactor=55459,2,6182770,1,49,0
Pfactor=19249,2,6185138,1,49,0
Pfactor=19249,2,6185858,1,49,0
Pfactor=55459,2,6187594,1,49,0
Pfactor=22699,2,6191038,1,49,0
Pfactor=28433,2,6195265,1,49,0
Pfactor=4847,2,6220431,1,49,0
Pfactor=10223,2,6226937,1,49,0
Pfactor=4847,2,6281463,1,49,0
Pfactor=28433,2,6345265,1,49,0
Pfactor=28433,2,6350497,1,49,0
Pfactor=55459,2,6358546,1,49,0
Pfactor=10223,2,6360365,1,49,0
Pfactor=24737,2,6363511,1,49,0
Pfactor=19249,2,6364058,1,49,0

Thanks Nuri! The 3 times the program did not find the factor is easily explained by the factor not lying within the B1/B2 values chosen by the optimal bounds checker.

Remember, when P-1 was first run on these numbers, sieving has only been done to 2^47 or so. I'll bet if you cahnged the 49 to 47 in the pfactor= lines, then these would be rediscovered too.

In summary, the program found 27 out of 27 factors that it should have found. That is encouraging. Feel free to use it on new k/n pairs.

I'll retest the 4,000,000 to 4,100,000 range you posted with different settings.

I started to test the last 3 numbers:

Pfactor=10223,2,6360365,1,49,0
Pfactor=24737,2,6363511,1,49,0
Pfactor=19249,2,6364058,1,49,0

The first one was correct, plus it

- used higher bounds,
- completed faster (~45 mins vs. ~65 mins) and
- was used for higher n's than before (6.3M vs. 6.0M).

Very good results, indeed! :cheers:

But the second test gave me a SUMOUT error just at the beginning. I first thought it would be my hardware, but the problem occurs right from the start and is reproducable - but only for this test (of the 3 I have)!

As the other 2 use a 512K FFT and the one in question 640K FFT, maybe this is the problem.
Additionally, the line "Zero-padded FFTs not coded yet!" is written for the problematic test.

On a sidenote, I found a crash bug. Once the program wanted to restart after the 5 minutes penalty, it gave me this little fellow:

George,
Could you please explain why some tests are being skipped. There doesn't seem to be any pattern...

Testing 20 more tests at the end (all beginning from Pfactor=21181,2,6167900,1,49,0 inclusive).

49 means the client assumes the k/n pair was sieved to 2^49, right?

If so, I guess we should use 48 there. What would you recommend?

I retested the 4000000 to 4100000 range with 47 instead of 49 and found all the factors.

I can reproduce the "Pfactor=24737,2,6363511,1,49,0" bug. Thanks for finding it! You've hit a case where I haven't finished the code yet. I didn't think we'd hit that case, but apparently there is a way.... I'll work on that soon.

Quote:

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Originally posted by garo
Could you please explain why some tests are being skipped. There doesn't seem to be any pattern...

---

The main "problem" is using 49 instead of 47 for these QA tests.

However, you are probably referring to the fact that some n values are skipped even though a slightly smaller n and slightly larger n are not. The short answer is that, unlike the previous version, the value of k affects the FFT size chosen. Larger k values will switch to a larger FFT size sooner that smaller k values. Larger FFT sizes affect how many temporary variables can be allocated in the memory the program is allowed to use, which in turn affects the optimal bounds selection.

Quote:

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Originally posted by Nuri
49 means the client assumes the k/n pair was sieved to 2^49, right?
If so, I guess we should use 48 there. What would you recommend?

---

For QA purposes we should probably use 48 or 47, whatever was commonly used at the time the factors were originally found.

For new work, I think you should use 49 as, from what I've read, you seem to have sieved to 2^49.

Will it be possible to make a new linux-factorer also?

Quote:

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Originally posted by prime95
For new work, I think you should use 49 as, from what I've read, you seem to have sieved to 2^49.

---

Sieving levels to certain exponents can be seen here (second table). 2^48 is almost completely sieved, 2^48 - 2^49 only to less than 10%.
Or is it important that everything to 2^49 has been sieved to approx. 55%?

I've uploaded a new sobpm1.zip that works around the 640K FFT problem. Instead you'll see several warnings about using a larger FFT size instead. The warnings can be ignored for now.

I've fixed the current_time crash bug after the 5 minute waiting period.

I'll see if I can build a Linux version.

As to whether you should use 49 or 48: Technically, you should use whatever value the siever will have reached by the time PRP testing will begin. So if you P-1 a 6 million exponent you should select 48 or 49 (either is fine as you are now at 48.55). If you were testing an exponent around 13 million, you might use 51 or 52.
In any event, don't get hung up on it. The smaller the number, the deeper the bounds that will be chosen.

Linux version, totally untested: ftp://mersenne.org/gimps/sobpm1.tgz

Can we expect any improvement in the future for non-SSE2 processors?

Seems it works OK for Linux also.

Code:

---

[Fri Jun 11 00:05:52 2004]
P-1 found a factor in stage #1, B1=30000.
4847*2^5801991+1 has a factor: 2015485189907779
[Fri Jun 11 00:34:42 2004]
P-1 found a factor in stage #2, B1=30000, B2=277500.
21181*2^5804804+1 has a factor: 5172107658035209

---

I'll keep it running for some more hours ...

Quote:

---

Originally posted by prime95
I've uploaded a new sobpm1.zip that works around the 640K FFT problem. Instead you'll see several warnings about using a larger FFT size instead. The warnings can be ignored for now.

---

Trying to factor "Pfactor=55459,2,6172258,1,49,0", I first got this output:


followed by another crash:



The problematic test from yesterday does work now, although it now uses a FFT size of 768K instead of 640K it tried earlier. Is this ok?
Of course, it takes a lot more time now - maybe 75% more...

Another thing that came to my mind. Assuming that there are two tests with the same n value, the associated file ("I<n>" - or is it "l<n>"?) of the first test will be overwritten, won't it?

Just for curiosity:
Is the release version any faster than the debug version?

Oooops!

That happens when I want to use test/status with the SOBPM1R client.

[Fri Jun 11 08:33:36 2004]
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.
Zero-padded FFTs not coded yet! Using larger FFT size.

Thanks George. I was referring to the skipping. It is interesting to see that k affects the optimal bounds so much and makes P-1 "seem" even more non-deterministic than in GIMPS.

I've read the source code that chooses P-1 bounds several times. I believe I know how it works. And it is not intuitive. So near FFT boundaries one cannot really say what bounds will be chosen. But I am convinced that it is optimal.

Finally, I believe that 48 is the correct bound for the moment (i.e. for 6M exponents) as only 10% of the range above 2^48 has been sieved. So we are really at 48.1 and not 48.55.

Mystwalker's latest debug assertion error is not good. For now, I'd stay away from those tests that are raising the "zero padded fft not coded yet" warning. I'll work on that soon.

Answering other questions:

The release version is not faster than the debug version.

The same improvements will come to the x87 code too. It will take quite a while. Since coding for SSE2 processors is a lot easier, I try out new ideas there first.

I'll fix the save file name problem and test/status bugs too. Thanks for the valuable QA testing.

???

55459*2^6399406+1 does not need P-1 factoring.

Quote:

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Originally posted by Nuri
???

55459*2^6399406+1 does not need P-1 factoring.

---

what is your memory settings in Options/CPU?

This later happened 12 more times.

13 occurances in a set a 30 workunits.

PS: Pfactor= settings were as usual.