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2016-10-14, 03:08   #361
EdH

"Ed Hall"
Dec 2009

5×727 Posts

Quote:
 Originally Posted by VBCurtis For GNFS jobs, I start sieving at 1/3rd of the factor base bound. The original factmsieve script started at 1/2 the bound, so somewhere in that range is reasonable. If your tools don't supply a default factor base (factmsieve.py does) it doesn't matter very much (within a factor of two of "best", say) what factor-base bounds you pick; perhaps 30M for the bounds with sieving starting at 12M should work fine. 14e is probly best; if you want to play with a little test-sieving, try using 14e the regular way and also invoking with with "-J 12" in the flag list. The latter may be a bit faster, at the expense of less yield (and thus a larger range of Q to be sieved).
Unfortunately, I don't understand factor base. I am doing everything manually although I have some scripts I wrote to distribute sieving and ECMing among my machines. I have used factmsieve.py in the past and even modified a version to work with my cluster I had running then. I should probably resurrect that script...

I was out all day, so I didn't try the "-j 12" switch this time - maybe next.

Quote:
 Originally Posted by henryzz ... You can run the script telling it you have run 0 curves (0@3e6 or something like that).
Excellent! This works great. I will do this and use the returned values to seed my ECM script from now on.

On the good side, I was able to build a matrix with a little over 36M unique relations and I have LA running on my cluster. I should have the factors in the morning:
Code:
Thu Oct 13 22:32:44 2016  Msieve v. 1.53 (SVN 993)
Thu Oct 13 22:32:44 2016  random seeds: 78202805 bdd4a0ec
Thu Oct 13 22:32:44 2016  MPI process 0 of 3
Thu Oct 13 22:32:44 2016  factoring 131954905347588391934699304738827948133275634558635457624548533060467418907362122329509131668522067078677069743086471484822031174847391546400311 (144 digits)
Thu Oct 13 22:32:46 2016  searching for 15-digit factors
Thu Oct 13 22:32:47 2016  commencing number field sieve (144-digit input)
Thu Oct 13 22:32:47 2016  R0: -10853864674370357346890831166
Thu Oct 13 22:32:47 2016  R1: 2070175205206213
Thu Oct 13 22:32:47 2016  A0: 1567149971784611966940117631701000925
Thu Oct 13 22:32:47 2016  A1: 57830699450094690463301740533
Thu Oct 13 22:32:47 2016  A2: -399896828755837210648218
Thu Oct 13 22:32:47 2016  A3: -58194781578947499
Thu Oct 13 22:32:47 2016  A4: -6125301397
Thu Oct 13 22:32:47 2016  A5: 876
Thu Oct 13 22:32:47 2016  skew 5656895.57, size 6.878e-14, alpha -6.666, combined = 1.347e-11 rroots = 3
Thu Oct 13 22:32:47 2016
Thu Oct 13 22:32:47 2016  commencing linear algebra
Thu Oct 13 22:32:47 2016  initialized process (0,0) of 3 x 1 grid
Thu Oct 13 22:32:48 2016  read 2789376 cycles
Thu Oct 13 22:32:57 2016  cycles contain 8822764 unique relations
Thu Oct 13 22:34:58 2016  read 8822764 relations
Thu Oct 13 22:35:10 2016  using 20 quadratic characters above 4294917295
Thu Oct 13 22:35:51 2016  building initial matrix
Thu Oct 13 22:37:43 2016  memory use: 1208.9 MB
Thu Oct 13 22:37:46 2016  read 2789376 cycles
Thu Oct 13 22:37:46 2016  matrix is 2789288 x 2789376 (849.1 MB) with weight 269812589 (96.73/col)
Thu Oct 13 22:37:46 2016  sparse part has weight 189118354 (67.80/col)
Thu Oct 13 22:38:18 2016  filtering completed in 2 passes
Thu Oct 13 22:38:19 2016  matrix is 2786778 x 2786925 (848.9 MB) with weight 269715636 (96.78/col)
Thu Oct 13 22:38:19 2016  sparse part has weight 189092868 (67.85/col)
Thu Oct 13 22:38:41 2016  matrix starts at (0, 0)
Thu Oct 13 22:38:41 2016  matrix is 929002 x 2786925 (372.8 MB) with weight 144909846 (52.00/col)
Thu Oct 13 22:38:41 2016  sparse part has weight 64287078 (23.07/col)
Thu Oct 13 22:38:41 2016  saving the first 48 matrix rows for later
Thu Oct 13 22:38:42 2016  matrix includes 64 packed rows
Thu Oct 13 22:38:42 2016  matrix is 928954 x 2786925 (346.7 MB) with weight 89762927 (32.21/col)
Thu Oct 13 22:38:42 2016  sparse part has weight 63022146 (22.61/col)
Thu Oct 13 22:38:42 2016  using block size 8192 and superblock size 294912 for processor cache size 3072 kB
Thu Oct 13 22:38:46 2016  commencing Lanczos iteration (2 threads)
Thu Oct 13 22:38:46 2016  memory use: 245.8 MB
Thu Oct 13 22:39:05 2016  linear algebra at 0.1%, ETA 9h 9m
Thu Oct 13 22:39:11 2016  checkpointing every 310000 dimensions