Decided to try an early filtering run to get an idea of how many relations would be needed to build a matrix, and unexpectedly found I already had enough:

Code:

Thu Sep 24 13:58:53 2020 Msieve v. 1.54 (SVN 1030M)
Thu Sep 24 13:58:53 2020 random seeds: ef4162b7 451c1899
Thu Sep 24 13:58:53 2020 factoring 804578163904697763240436614199214815395940531796301633839037380172577453559153269748944116985171617459275488471139711654222671571416371470668646221173373030303086767051992380630291851 (183 digits)
Thu Sep 24 13:58:54 2020 searching for 15-digit factors
Thu Sep 24 13:58:54 2020 commencing number field sieve (183-digit input)
Thu Sep 24 13:58:54 2020 R0: -271295764750414187331730229412933346
Thu Sep 24 13:58:54 2020 R1: 1815599719426695021034001
Thu Sep 24 13:58:54 2020 A0: -157759777296013619586250253003236919241978
Thu Sep 24 13:58:54 2020 A1: 208393498976386503111847358887987939
Thu Sep 24 13:58:54 2020 A2: 1903348446157907742464167536
Thu Sep 24 13:58:54 2020 A3: -28655357853458133620365
Thu Sep 24 13:58:54 2020 A4: -145343027262384
Thu Sep 24 13:58:54 2020 A5: 59126760
Thu Sep 24 13:58:54 2020 skew 5738604.63, size 5.111e-18, alpha -6.698, combined = 4.768e-14 rroots = 5
Thu Sep 24 13:58:54 2020
Thu Sep 24 13:58:54 2020 commencing relation filtering
Thu Sep 24 13:58:54 2020 setting target matrix density to 100.0
Thu Sep 24 13:58:54 2020 estimated available RAM is 15845.8 MB
Thu Sep 24 13:58:54 2020 commencing duplicate removal, pass 1
...
Thu Sep 24 14:37:47 2020 found 96535007 hash collisions in 371534711 relations
Thu Sep 24 14:38:09 2020 added 121654 free relations
Thu Sep 24 14:38:09 2020 commencing duplicate removal, pass 2
Thu Sep 24 14:46:01 2020 found 108284827 duplicates and 263371538 unique relations
Thu Sep 24 14:46:01 2020 memory use: 2387.0 MB
Thu Sep 24 14:46:01 2020 reading ideals above 186974208
Thu Sep 24 14:46:01 2020 commencing singleton removal, initial pass
Thu Sep 24 15:06:32 2020 memory use: 6024.0 MB
Thu Sep 24 15:06:32 2020 reading all ideals from disk
Thu Sep 24 15:07:11 2020 memory use: 4787.5 MB
Thu Sep 24 15:07:19 2020 commencing in-memory singleton removal
Thu Sep 24 15:07:26 2020 begin with 263371538 relations and 255561661 unique ideals
Thu Sep 24 15:08:37 2020 reduce to 123121291 relations and 95945973 ideals in 17 passes
Thu Sep 24 15:08:37 2020 max relations containing the same ideal: 35
Thu Sep 24 15:08:46 2020 reading ideals above 720000
Thu Sep 24 15:08:46 2020 commencing singleton removal, initial pass
Thu Sep 24 15:24:11 2020 memory use: 3012.0 MB
Thu Sep 24 15:24:12 2020 reading all ideals from disk
Thu Sep 24 15:24:56 2020 memory use: 5110.3 MB
Thu Sep 24 15:25:06 2020 keeping 116085117 ideals with weight <= 200, target excess is 643178
Thu Sep 24 15:25:17 2020 commencing in-memory singleton removal
Thu Sep 24 15:25:25 2020 begin with 123121291 relations and 116085117 unique ideals
Thu Sep 24 15:27:04 2020 reduce to 123023063 relations and 115986878 ideals in 13 passes
Thu Sep 24 15:27:04 2020 max relations containing the same ideal: 200
Thu Sep 24 15:27:50 2020 removing 8828550 relations and 7828550 ideals in 1000000 cliques
Thu Sep 24 15:27:52 2020 commencing in-memory singleton removal
Thu Sep 24 15:28:00 2020 begin with 114194513 relations and 115986878 unique ideals
Thu Sep 24 15:29:18 2020 reduce to 113693675 relations and 107651902 ideals in 11 passes
Thu Sep 24 15:29:18 2020 max relations containing the same ideal: 198
Thu Sep 24 15:30:00 2020 removing 6670193 relations and 5670193 ideals in 1000000 cliques
Thu Sep 24 15:30:03 2020 commencing in-memory singleton removal
Thu Sep 24 15:30:10 2020 begin with 107023482 relations and 107651902 unique ideals
Thu Sep 24 15:31:10 2020 reduce to 106698207 relations and 101653297 ideals in 9 passes
Thu Sep 24 15:31:10 2020 max relations containing the same ideal: 193
Thu Sep 24 15:31:49 2020 removing 6014282 relations and 5014282 ideals in 1000000 cliques
Thu Sep 24 15:31:52 2020 commencing in-memory singleton removal
Thu Sep 24 15:31:58 2020 begin with 100683925 relations and 101653297 unique ideals
Thu Sep 24 15:32:55 2020 reduce to 100396164 relations and 96348603 ideals in 9 passes
Thu Sep 24 15:32:55 2020 max relations containing the same ideal: 184
Thu Sep 24 15:33:33 2020 removing 5675031 relations and 4675031 ideals in 1000000 cliques
Thu Sep 24 15:33:35 2020 commencing in-memory singleton removal
Thu Sep 24 15:33:41 2020 begin with 94721133 relations and 96348603 unique ideals
Thu Sep 24 15:34:28 2020 reduce to 94444992 relations and 91394891 ideals in 8 passes
Thu Sep 24 15:34:28 2020 max relations containing the same ideal: 180
Thu Sep 24 15:35:03 2020 removing 5474215 relations and 4474215 ideals in 1000000 cliques
Thu Sep 24 15:35:05 2020 commencing in-memory singleton removal
Thu Sep 24 15:35:11 2020 begin with 88970777 relations and 91394891 unique ideals
Thu Sep 24 15:36:01 2020 reduce to 88694416 relations and 86641692 ideals in 9 passes
Thu Sep 24 15:36:01 2020 max relations containing the same ideal: 171
Thu Sep 24 15:36:35 2020 removing 5350364 relations and 4350365 ideals in 1000000 cliques
Thu Sep 24 15:36:37 2020 commencing in-memory singleton removal
Thu Sep 24 15:36:42 2020 begin with 83344052 relations and 86641692 unique ideals
Thu Sep 24 15:37:28 2020 reduce to 83062640 relations and 82007106 ideals in 9 passes
Thu Sep 24 15:37:28 2020 max relations containing the same ideal: 165
Thu Sep 24 15:37:59 2020 removing 2035095 relations and 1725648 ideals in 309447 cliques
Thu Sep 24 15:38:01 2020 commencing in-memory singleton removal
Thu Sep 24 15:38:06 2020 begin with 81027545 relations and 82007106 unique ideals
Thu Sep 24 15:38:36 2020 reduce to 80987675 relations and 80241438 ideals in 6 passes
Thu Sep 24 15:38:36 2020 max relations containing the same ideal: 163
Thu Sep 24 15:39:17 2020 relations with 0 large ideals: 2387
Thu Sep 24 15:39:17 2020 relations with 1 large ideals: 2644
Thu Sep 24 15:39:17 2020 relations with 2 large ideals: 48967
Thu Sep 24 15:39:17 2020 relations with 3 large ideals: 476525
Thu Sep 24 15:39:17 2020 relations with 4 large ideals: 2541197
Thu Sep 24 15:39:17 2020 relations with 5 large ideals: 8234652
Thu Sep 24 15:39:17 2020 relations with 6 large ideals: 16947934
Thu Sep 24 15:39:17 2020 relations with 7+ large ideals: 52733369
Thu Sep 24 15:39:17 2020 commencing 2-way merge
Thu Sep 24 15:40:00 2020 reduce to 49697082 relation sets and 48950844 unique ideals
Thu Sep 24 15:40:00 2020 commencing full merge
Thu Sep 24 15:51:57 2020 memory use: 5812.0 MB
Thu Sep 24 15:52:01 2020 found 23504201 cycles, need 23427044
Thu Sep 24 15:52:07 2020 weight of 23427044 cycles is about 2342739929 (100.00/cycle)
Thu Sep 24 15:52:07 2020 distribution of cycle lengths:
Thu Sep 24 15:52:07 2020 1 relations: 2500861
Thu Sep 24 15:52:07 2020 2 relations: 2225344
Thu Sep 24 15:52:07 2020 3 relations: 2213648
Thu Sep 24 15:52:07 2020 4 relations: 2063640
Thu Sep 24 15:52:07 2020 5 relations: 1936571
Thu Sep 24 15:52:07 2020 6 relations: 1794380
Thu Sep 24 15:52:07 2020 7 relations: 1614061
Thu Sep 24 15:52:07 2020 8 relations: 1433750
Thu Sep 24 15:52:07 2020 9 relations: 1293116
Thu Sep 24 15:52:07 2020 10+ relations: 6351673
Thu Sep 24 15:52:07 2020 heaviest cycle: 27 relations
Thu Sep 24 15:52:11 2020 commencing cycle optimization
Thu Sep 24 15:52:40 2020 start with 162941027 relations
Thu Sep 24 15:56:11 2020 pruned 4844744 relations
Thu Sep 24 15:56:12 2020 memory use: 4991.4 MB
Thu Sep 24 15:56:12 2020 distribution of cycle lengths:
Thu Sep 24 15:56:12 2020 1 relations: 2500861
Thu Sep 24 15:56:12 2020 2 relations: 2281779
Thu Sep 24 15:56:12 2020 3 relations: 2297419
Thu Sep 24 15:56:12 2020 4 relations: 2125272
Thu Sep 24 15:56:12 2020 5 relations: 1998705
Thu Sep 24 15:56:12 2020 6 relations: 1832292
Thu Sep 24 15:56:12 2020 7 relations: 1647060
Thu Sep 24 15:56:12 2020 8 relations: 1454221
Thu Sep 24 15:56:12 2020 9 relations: 1305171
Thu Sep 24 15:56:12 2020 10+ relations: 5984264
Thu Sep 24 15:56:12 2020 heaviest cycle: 27 relations
Thu Sep 24 15:56:51 2020 RelProcTime: 7077
Thu Sep 24 15:56:59 2020
Thu Sep 24 15:56:59 2020 commencing linear algebra
Thu Sep 24 15:57:01 2020 read 23427044 cycles
Thu Sep 24 15:57:36 2020 cycles contain 80452255 unique relations
Thu Sep 24 16:06:39 2020 read 80452255 relations
Thu Sep 24 16:08:27 2020 using 20 quadratic characters above 4294917295
Thu Sep 24 16:13:36 2020 building initial matrix
Thu Sep 24 16:26:16 2020 memory use: 11291.7 MB
Thu Sep 24 16:27:47 2020 read 23427044 cycles
Thu Sep 24 16:27:50 2020 matrix is 23426866 x 23427044 (9592.6 MB) with weight 2929149922 (125.03/col)
Thu Sep 24 16:27:50 2020 sparse part has weight 2233524910 (95.34/col)
Thu Sep 24 16:31:09 2020 filtering completed in 2 passes
Thu Sep 24 16:31:13 2020 matrix is 23423858 x 23424036 (9592.4 MB) with weight 2929033628 (125.04/col)
Thu Sep 24 16:31:13 2020 sparse part has weight 2233502594 (95.35/col)
Thu Sep 24 16:34:27 2020 matrix starts at (0, 0)
Thu Sep 24 16:34:30 2020 matrix is 23423858 x 23424036 (9592.4 MB) with weight 2929033628 (125.04/col)
Thu Sep 24 16:34:30 2020 sparse part has weight 2233502594 (95.35/col)
Thu Sep 24 16:34:30 2020 saving the first 48 matrix rows for later
Thu Sep 24 16:34:33 2020 matrix includes 64 packed rows
Thu Sep 24 16:34:36 2020 matrix is 23423810 x 23424036 (9296.0 MB) with weight 2454035299 (104.77/col)
Thu Sep 24 16:34:36 2020 sparse part has weight 2202649119 (94.03/col)
Thu Sep 24 16:34:36 2020 using block size 8192 and superblock size 884736 for processor cache size 9216 kB
Thu Sep 24 16:35:39 2020 commencing Lanczos iteration (6 threads)
Thu Sep 24 16:35:40 2020 memory use: 8970.1 MB
Thu Sep 24 16:36:45 2020 linear algebra at 0.0%, ETA 265h12m
Thu Sep 24 16:37:06 2020 checkpointing every 90000 dimensions

I was caught out by the fact that the duplication rate is substantially lower than it was on the 31/32 runs; Curtis, you were right about 32/32 needing 30% more *unique* relations than 31/32.

I can't immediately see why raising the lpb on the rational side while sieving on the algebraic side ought to have anything to do with the duplication rate, but I'm not a number theorist so I'd appreciate it if someone could explain this.

It's looking like 32/32 is a win at this size. As usual I'll have more details once I've got the matrix size down.