Msieve 1.51 feedback - Page 20

jasonp · 2013-07-20, 19:24

I can reproduce the behavior locally. Debug in progress.

Edit: if your number contains small factors, please divide them all out before running NFS using Msieve. The library did this for you, which made the NFS input different from the library input, which is a fatal error that is reported very badly. In this particular case, you must insure that R0^6 + 93*R1^6 = N, where N is what you give both the .fb file and the ini file.

fivemack · 2013-07-20, 20:36

It may help some people to know that the default -march=core2 build, with gcc-4.6, produces code for get_merge_memuse that uses the SSSE3 'pshufb %xmm1, %xmm2' instruction, which even the Opteron 61xx-series processors don't support. I may be the only person with so old a computer, and the problem only appeared when I upgraded the 48-core from ubuntu-10.04 to ubuntu-12.04

Changing to -march=barcelona and re-running five hours of filtering

Jeff Gilchrist · 2013-07-21, 00:46

I have now posted the latest SVN927 from Brian on my website:
http://gilchrist.ca/jeff/factoring/index.html

This should just be linked to the VS2012 DLL so you should just need the vcomp110.dll now (VS2012 Redistributable Package) that you can find the link off my website if you need it.

Mathew · 2013-07-22, 03:24

Quote:

Originally Posted by jasonp

I can reproduce the behavior locally. Debug in progress.

Edit: if your number contains small factors, please divide them all out before running NFS using Msieve. The library did this for you, which made the NFS input different from the library input, which is a fatal error that is reported very badly. In this particular case, you must insure that R0^6 + 93*R1^6 = N, where N is what you give both the .fb file and the ini file.

Yes,
This resolved the issue.

Thanks everyone

WraithX · 2013-07-22, 12:52

Quote:

Originally Posted by Jeff Gilchrist

I have now posted the latest SVN927 from Brian on my website:
http://gilchrist.ca/jeff/factoring/index.html

This should just be linked to the VS2012 DLL so you should just need the vcomp110.dll now (VS2012 Redistributable Package) that you can find the link off my website if you need it.

Good news everyone! This version worked splendidly on the L1911 C167. It was able to complete an 8.83M^2 matrix in 21.5 hours with 16 threads. I'm currently testing it with 8 threads to see how the time changes. I'll let you know when it is done.

A big Thank You! to both Brian and Jeff for compiling/updating/testing msieve to get this to work and to Jeff for hosting the binary. Thank You!

fivemack · 2013-07-22, 18:29

Would you mind posting the numbers on

http://www.mersenneforum.org/showthread.php?t=18374

once you've got them?

WraithX · 2013-07-23, 00:16

Quote:

Originally Posted by fivemack

Would you mind posting the numbers on

http://www.mersenneforum.org/showthread.php?t=18374

once you've got them?

Sure thing. If you don't mind waiting for a bit, I'll even try to get timings for all the even numbered thread counts (2,4,6,8,10,12,14,16, maybe even 1). Since I don't have an MPI library and I don't have an MPI msieve, I may not be getting the most out of this machine. But, it still seems to be performing rather well. Just as a preview, when I last checked, it looked like the total eta for 8 threads was around 22.x hours. So, not too much benefit to running 16 threads vs 8 threads, but I think every little bit helps if/when I run larger and larger jobs on this. I'll post all the timings, in that thread, when I have them.

Jarod · 2013-08-01, 07:01

Quote:

Originally Posted by Jeff Gilchrist

I have now posted the latest SVN927 from Brian on my website:
http://gilchrist.ca/jeff/factoring/index.html

This should just be linked to the VS2012 DLL so you should just need the vcomp110.dll now (VS2012 Redistributable Package) that you can find the link off my website if you need it.

I ran a test using SVN 927 everything ran fine up until

Code:

Thu Aug 01 15:57:30 2013  commencing Lanczos iteration (6 threads)
Thu  Aug 01 15:57:30 2013  memory use: 3433.0 MB

then the application just come up with the window on my screen saying stopped working.
one thing I did note though I have never seen the line

Code:

commencing  Lanczos iteration

in my log before. Is this a new phase?
I have attached the log and my start a bat file. I have successfully managed to run the I 7 test file without incident. I have also attached the successful run log.

ryanp · 2013-08-07, 06:09

I'm seeing a similar issue when trying to run msieve on the 299-digit cofactor of http://www.factordb.com/index.php?id...00000043596293, 372889817...

Code:

Msieve v. 1.52 (SVN 936)
Tue Aug  6 23:06:33 2013
random seeds: 2e3714b9 5c9bc30e
factoring 37288981771039578285751767666152422444740872141841696556525922548756411612078722511313217745832358082426302486574369734100797157544170974891788191605290166523358074421434377183830973607149873256496995571602300206060954537411516595930389968935728417411471833743940981915375445496229631862855442183381 (299 digits)
no P-1/P+1/ECM available, skipping
commencing number field sieve (299-digit input)
warning: NFS input not found in factor base file
integrator failed nan inf
R0: 0
A0: 0
skew 1.00, size 0.000e+00, alpha 0.000, combined = 0.000e+00 rroots = 0

commencing relation filtering
warning: NFS input not found in factor base file
estimated available RAM is 12015.3 MB
commencing duplicate removal, pass 1
Segmentation fault (core dumped)

Here's input.fb:

Code:

N 37288981771039578285751767666152422444740872141841696556525922548756411612078722511313217745832358082426302486574369734100797157544170974891788191605290166523358074421434377183830973607149873256496995571602300206060954537411516595930389968935728417411471833743940981915375445496229631862855442183381
SKEW 1.53
A6 1
A0 -13
R1 1
R0 -134106816713249934153658112422086110743809315028093
FAMAX 727400000
FRMAX 727400000
SALPMAX 8589934592
SRLPMAX 8589934592

And input.ini, which of course is just n:

Code:

37288981771039578285751767666152422444740872141841696556525922548756411612078722511313217745832358082426302486574369734100797157544170974891788191605290166523358074421434377183830973607149873256496995571602300206060954537411516595930389968935728417411471833743940981915375445496229631862855442183381

I don't see anything obviously wrong here; is this a different issue?

sashamkrt · 2013-08-07, 06:23

I've tried to search poly for 3,664+1, but I can't understand why msieve generates different polys for the same C5.

For instance,
msieve.exe -np1 293700,293701
msieve.exe -nps "stage2_norm=2.0e+26"
msieve.exe -npr "min_evalue=1.0e-14"

first_run (msieve.dat.ms)
293700 1397440288541986 4478065234141680360882817 -2646467642417801303869024298 -3599037771632009548120018107216510709 634456441079135352336684238962817871111 312509308878988211203 -15926882136722045449097144514629677396 -1.48 8.253952e+025
second run:
293700 1829556961989992 7964401858144116000145295 -16290668681053306780662697488 -30191334832372427186210377555496771461 18342641143578897062225246421826683577631 291377541254794571903 -15926882071091321988301200975327033344 -1.94 1.362999e+026
third run:
293700 -3057506938837243 -4067250878705725413749304 61572828282060473603942651797 34905381927171164712790251745494442467 -156920916090391208277241328651760917010842 203997302334302799943 -15926882858844157268904316424670420895 -1.48 1.355203e+026
293700 -202924021073258 6080305114498964037396469 1345235070165910556666877880 -17509455271765713730856017988411871119 -1144573362330082304893085355558960151909 346080882673041852263 -15926882481932252427695730686237341092 -1.48 1.541913e+026
293700 -92275958057363 -5838513017255197123041550 507762258296670036318237684 13479765598879587657730718111429015834 -341387246780453842740135044603911369823 269229725042974558717 -15926882451026824041231354533379949130 -1.48 1.401040e+026

msieve_gpu also generates different polys each time i ran it with the same params.
Is it normal? How can I be sure if I don't miss a good poly?

One more thing, if I find a good poly for an exact A5. Can I find a better one running poly search for the same A5 many times?

chris2be8 · 2013-08-07, 16:20

@ryanp, it sounds as if you are trying to use msieve to do the sieving. Bur it only has a line siever which is nearly useless. You need the GGNFS lattice sievers to do any useful sieving, see http://gilchrist.ca/jeff/factoring/n...ers_guide.html (especially the SNFS section at the bottom).

But to do a SNFS 299 job like that in a year would need NFS@HOME to do the sieving and a large cluster for linear algebra.

@sashamkrt, the search space is far too large for msieve to search it all, it just searches a random subset. So getting different results each time is normal. Either use the poly with the best score or do some trial sieving with the best few and use the one that sieves best (this is only worthwhile for a fairly large job though).

Chris

2013-07-20, 19:24	#210
jasonp Tribal Bullet Oct 2004 3,541 Posts	I can reproduce the behavior locally. Debug in progress. Edit: if your number contains small factors, please divide them all out before running NFS using Msieve. The library did this for you, which made the NFS input different from the library input, which is a fatal error that is reported very badly. In this particular case, you must insure that R0^6 + 93R1^6 = N, where N is what you give both the .fb file and the ini file. Last fiddled with by jasonp on 2013-07-20 at 19:41*

2013-07-20, 20:36	#211
fivemack (loop (#_fork)) Feb 2006 Cambridge, England 14423₈ Posts	Tiny issue It may help some people to know that the default -march=core2 build, with gcc-4.6, produces code for get_merge_memuse that uses the SSSE3 'pshufb %xmm1, %xmm2' instruction, which even the Opteron 61xx-series processors don't support. I may be the only person with so old a computer, and the problem only appeared when I upgraded the 48-core from ubuntu-10.04 to ubuntu-12.04 Changing to -march=barcelona and re-running five hours of filtering

2013-08-07, 06:23	#219
sashamkrt Aug 2013 31₈ Posts	Polynom question I've tried to search poly for 3,664+1, but I can't understand why msieve generates different polys for the same C5. For instance, msieve.exe -np1 293700,293701 msieve.exe -nps "stage2_norm=2.0e+26" msieve.exe -npr "min_evalue=1.0e-14" first_run (msieve.dat.ms) 293700 1397440288541986 4478065234141680360882817 -2646467642417801303869024298 -3599037771632009548120018107216510709 634456441079135352336684238962817871111 312509308878988211203 -15926882136722045449097144514629677396 -1.48 8.253952e+025 second run: 293700 1829556961989992 7964401858144116000145295 -16290668681053306780662697488 -30191334832372427186210377555496771461 18342641143578897062225246421826683577631 291377541254794571903 -15926882071091321988301200975327033344 -1.94 1.362999e+026 third run: 293700 -3057506938837243 -4067250878705725413749304 61572828282060473603942651797 34905381927171164712790251745494442467 -156920916090391208277241328651760917010842 203997302334302799943 -15926882858844157268904316424670420895 -1.48 1.355203e+026 293700 -202924021073258 6080305114498964037396469 1345235070165910556666877880 -17509455271765713730856017988411871119 -1144573362330082304893085355558960151909 346080882673041852263 -15926882481932252427695730686237341092 -1.48 1.541913e+026 293700 -92275958057363 -5838513017255197123041550 507762258296670036318237684 13479765598879587657730718111429015834 -341387246780453842740135044603911369823 269229725042974558717 -15926882451026824041231354533379949130 -1.48 1.401040e+026 msieve_gpu also generates different polys each time i ran it with the same params. Is it normal? How can I be sure if I don't miss a good poly? One more thing, if I find a good poly for an exact A5. Can I find a better one running poly search for the same A5 many times?

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2013-07-21, 00:46	#212
Jeff Gilchrist Jun 2003 Ottawa, Canada 3×17×23 Posts	I have now posted the latest SVN927 from Brian on my website: http://gilchrist.ca/jeff/factoring/index.html This should just be linked to the VS2012 DLL so you should just need the vcomp110.dll now (VS2012 Redistributable Package) that you can find the link off my website if you need it.

2013-07-22, 18:29	#215
fivemack (loop (#_fork)) Feb 2006 Cambridge, England 1100100010011₂ Posts	Would you mind posting the numbers on http://www.mersenneforum.org/showthread.php?t=18374 once you've got them?

2013-08-07, 16:20	#220
chris2be8 Sep 2009 100000011110₂ Posts	@ryanp, it sounds as if you are trying to use msieve to do the sieving. Bur it only has a line siever which is nearly useless. You need the GGNFS lattice sievers to do any useful sieving, see http://gilchrist.ca/jeff/factoring/n...ers_guide.html (especially the SNFS section at the bottom). But to do a SNFS 299 job like that in a year would need NFS@HOME to do the sieving and a large cluster for linear algebra. @sashamkrt, the search space is far too large for msieve to search it all, it just searches a random subset. So getting different results each time is normal. Either use the poly with the best score or do some trial sieving with the best few and use the one that sieves best (this is only worthwhile for a fairly large job though). Chris