Gratuitous factors thread

[unconnected]

Rather rare ECM hit - P50 with B1=1e6 on aliquot sequence 213720:i1748

06/22/22 10:47:52, scheduled 781 curves at B1=1000000 toward target pretesting depth of 34.77
06/22/22 10:56:22, prp50 = 10393259545295633660028312292669510525032755549983 (curve 576 stg2 B1=1000000 sigma=2114364744 thread=3)
06/22/22 10:56:23, Finished 578 curves using GMP-ECM method on C113 input, B1=1M, B2=gmp-ecm default

[fivemack]

Sat Jun 18 11:14:36 2022  commencing relation filtering
Sat Jun 18 11:14:36 2022  setting target matrix density to 130.0
Sat Jun 18 16:39:32 2022  found 253785883 hash collisions in 884618379 relations
Sat Jun 18 16:56:21 2022  found 249640336 duplicates and 634978043 unique relations
Sat Jun 18 21:50:05 2022  keeping 642646661 ideals with weight <= 200, target excess is 3337339
Sun Jun 19 03:10:29 2022  weight of 61398287 cycles is about 7982480398 (130.01/cycle)
Mon Jun 20 16:55:50 2022  matrix is 61396802 x 61397217 (28544.7 MB) with weight 6879882710 (112.06/col)
Mon Jun 20 16:55:50 2022  sparse part has weight 6500470301 (105.88/col)
Mon Jun 20 16:55:50 2022  using block size 8192 and superblock size 473088 for processor cache size 19712 kB
Mon Jun 20 16:58:58 2022  commencing Lanczos iteration (14 threads)
Mon Jun 20 16:58:58 2022  memory use: 39165.2 MB
Mon Jun 20 17:00:52 2022  linear algebra at 0.0%, ETA 1056h51m
Mon Jun 20 17:01:25 2022  checkpointing every 60000 dimensions
Thu Aug  4 01:20:22 2022  lanczos halted after 240551 iterations (dim = 61396800)
Thu Aug  4 01:24:54 2022  recovered 29 nontrivial dependencies
Thu Aug  4 01:25:11 2022  BLanczosTime: 3838234
Thu Aug  4 01:25:11 2022  elapsed time 1066:10:34
Thu Aug  4 09:03:42 2022  
Thu Aug  4 09:03:42 2022  
Thu Aug  4 09:03:42 2022  Msieve v. 1.54 (SVN 1030M)
Thu Aug  4 09:03:42 2022  random seeds: 13b713d5 bb171d5a
Thu Aug  4 09:03:42 2022  factoring 235690490213264657463900217730943824554528801527148146000741132394289637021389555084534044618776128084370642121517338234516897475536672909156227425053218472454497341488127093035620464801567308818878368161 (204 digits)
Thu Aug  4 09:03:42 2022  no P-1/P+1/ECM available, skipping
Thu Aug  4 09:03:42 2022  commencing number field sieve (204-digit input)
Thu Aug  4 09:03:42 2022  R0: -2530528376362098551295006697188264488331
Thu Aug  4 09:03:42 2022  R1: 869607471902015319334451
Thu Aug  4 09:03:42 2022  A0: 4794286155561978100243308360517944857334122844056
Thu Aug  4 09:03:42 2022  A1: 225816378627344837726832138347030302060794
Thu Aug  4 09:03:42 2022  A2: 93310870436284966139238827232264
Thu Aug  4 09:03:42 2022  A3: -8511608197480840558280241
Thu Aug  4 09:03:42 2022  A4: 425430523159498
Thu Aug  4 09:03:42 2022  A5: 2271360
Thu Aug  4 09:03:42 2022  skew 295921789.67, size 5.084e-20, alpha -7.573, combined = 2.642e-15 rroots = 5
Thu Aug  4 09:03:42 2022  
Thu Aug  4 09:03:42 2022  commencing square root phase
Thu Aug  4 09:03:42 2022  reading relations for dependency 1
Thu Aug  4 09:03:47 2022  read 30710593 cycles
Thu Aug  4 09:04:54 2022  cycles contain 112671476 unique relations
Thu Aug  4 09:12:29 2022  read 112671476 relations
Thu Aug  4 09:22:12 2022  multiplying 112671476 relations
Thu Aug  4 11:41:27 2022  multiply complete, coefficients have about 7305.03 million bits
Thu Aug  4 11:42:01 2022  initial square root is modulo 155615419
Thu Aug  4 14:14:51 2022  sqrtTime: 18669
Thu Aug  4 14:14:51 2022  p78 factor: 305243370577692687562023127362819254670248796601352698266538583812016117141423
Thu Aug  4 14:14:51 2022  p126 factor: 772139587396133334683063918926732402964306604392061079545291898181089775086186502933346070065885090044744147103538539121983407

About 394750 thread-hours on about 100 assorted-Xeon hyper threaded cores over three months to sieve, six weeks on 14 cores i9/7940X for linear algebra.

And that will be my last GNFS for at least six months: electricity prices went up 50% on 1 August and will probably do the same on 1 October, and it's not clear they won't repeat the feat on 1 February unless Russia has withdrawn from Ukraine. I've got one quite large machine finishing the linear algebra for a chunky GNFS, then that will be turned off too.