I've only got two log files from matrix runs that failed, and only one with a recent version:

[code]
/safe/cunningham/5,775M/msieve.log-Wed Feb 13 22:30:22 2008 matrix is 5025987 x 5026229 (1294.7 MB) with weight 349634052 (69.56/col)
/safe/cunningham/5,775M/msieve.log-Wed Feb 13 22:30:22 2008 sparse part has weight 279094804 (55.53/col)
/safe/cunningham/5,775M/msieve.log-Wed Feb 13 22:30:22 2008 matrix includes 128 packed rows
/safe/cunningham/5,775M/msieve.log-Wed Feb 13 22:30:22 2008 using block size 65536 for processor cache size 4096 kB
/safe/cunningham/5,775M/msieve.log-Wed Feb 13 22:30:52 2008 commencing Lanczos iteration (2 threads)
/safe/cunningham/5,775M/msieve.log-Wed Feb 13 22:30:52 2008 memory use: 1319.4 MB
/safe/cunningham/5,775M/msieve.log-Sun Feb 17 03:28:48 2008 lanczos halted after 79479 iterations (dim = 5025576)
/safe/cunningham/5,775M/msieve.log:Sun Feb 17 03:29:01 2008 lanczos error: only trivial dependencies found
[/code]

which would seem to confirm your hypothesis.

On the other hand,
[code]
/safe/homcun/11+10.184/msieve/msieve.log-Fri Feb 15 00:35:45 2008 matrix is 401907 x 402155 (103.5 MB) with weight 28957098 (72.00/col)
/safe/homcun/11+10.184/msieve/msieve.log-Fri Feb 15 00:35:45 2008 sparse part has weight 22300832 (55.45/col)
/safe/homcun/11+10.184/msieve/msieve.log-Fri Feb 15 00:35:45 2008 matrix includes 128 packed rows
/safe/homcun/11+10.184/msieve/msieve.log-Fri Feb 15 00:35:45 2008 using block size 65536 for processor cache size 4096 kB
/safe/homcun/11+10.184/msieve/msieve.log:Fri Feb 15 00:35:48 2008 commencing Lanczos iteration
/safe/homcun/11+10.184/msieve/msieve.log-Fri Feb 15 00:35:48 2008 memory use: 99.2 MB
/safe/homcun/11+10.184/msieve/msieve.log-Fri Feb 15 00:37:54 2008 lanczos error: submatrix is not invertible
/safe/homcun/11+10.184/msieve/msieve.log-Fri Feb 15 00:37:54 2008 lanczos halted after 540 iterations (dim = 34098)
/safe/homcun/11+10.184/msieve/msieve.log-Fri Feb 15 00:37:54 2008 linear algebra failed; retrying...
/safe/homcun/11+10.184/msieve/msieve.log:Fri Feb 15 00:37:54 2008 commencing Lanczos iteration
/safe/homcun/11+10.184/msieve/msieve.log-Fri Feb 15 00:37:54 2008 memory use: 99.2 MB
/safe/homcun/11+10.184/msieve/msieve.log-Fri Feb 15 01:02:36 2008 lanczos halted after 6358 iterations (dim = 401902)
/safe/homcun/11+10.184/msieve/msieve.log-Fri Feb 15 01:02:37 2008 recovered 40 nontrivial dependencies
[/code]

Initial matrix for 3^512+1
 

[code]
Tue Apr 29 23:48:00 2008 Msieve v. 1.34
Tue Apr 29 23:48:00 2008 random seeds: 5f6708ca 737b360c
Tue Apr 29 23:48:00 2008 factoring 2652879528384736294387787089866884113161756949676609780113021980279955578028580515829763316598420245173034168388765124717208315443806148182904105317960270313646866242717807445467423472021744641 (193 digits)
Tue Apr 29 23:53:40 2008 restarting with 189612490 relations
Wed Apr 30 00:19:08 2008 found 48513490 hash collisions in 189611855 relations
Wed Apr 30 00:19:08 2008 commencing duplicate removal, pass 2
Wed Apr 30 00:35:48 2008 found 16908240 duplicates and 172703615 unique relations
Wed Apr 30 00:35:48 2008 memory use: 1911.0 MB
Wed Apr 30 00:35:49 2008 ignoring smallest 183072 rational and 182532 algebraic ideals
Wed Apr 30 00:35:49 2008 filtering rational ideals above 2500000
Wed Apr 30 00:35:49 2008 filtering algebraic ideals above 2500000
Wed Apr 30 00:35:49 2008 need 548406 more relations than ideals
Wed Apr 30 00:35:49 2008 commencing singleton removal, pass 1
Wed Apr 30 01:02:44 2008 relations with 0 large ideals: 0
Wed Apr 30 01:02:44 2008 relations with 1 large ideals: 742
Wed Apr 30 01:02:44 2008 relations with 2 large ideals: 25483
Wed Apr 30 01:02:44 2008 relations with 3 large ideals: 356357
Wed Apr 30 01:02:44 2008 relations with 4 large ideals: 2687291
Wed Apr 30 01:02:44 2008 relations with 5 large ideals: 11751148
Wed Apr 30 01:02:44 2008 relations with 6 large ideals: 30511295
Wed Apr 30 01:02:44 2008 relations with 7+ large ideals: 127371299
Wed Apr 30 01:02:44 2008 172703615 relations and about 96169746 large ideals
Wed Apr 30 01:02:44 2008 commencing singleton removal, pass 2
Wed Apr 30 01:29:41 2008 found 15878777 singletons
Wed Apr 30 01:29:41 2008 current dataset: 156824838 relations and about 79705795 large ideals
Wed Apr 30 01:29:42 2008 commencing singleton removal, pass 3
Wed Apr 30 01:54:36 2008 relations with 0 large ideals: 0
Wed Apr 30 01:54:36 2008 relations with 1 large ideals: 742
Wed Apr 30 01:54:36 2008 relations with 2 large ideals: 24904
Wed Apr 30 01:54:36 2008 relations with 3 large ideals: 341002
Wed Apr 30 01:54:36 2008 relations with 4 large ideals: 2520743
Wed Apr 30 01:54:36 2008 relations with 5 large ideals: 10848320
Wed Apr 30 01:54:36 2008 relations with 6 large ideals: 27860172
Wed Apr 30 01:54:36 2008 relations with 7+ large ideals: 115228955
Wed Apr 30 01:54:36 2008 156824838 relations and about 114324560 large ideals
Wed Apr 30 01:54:36 2008 commencing singleton removal, pass 4
Wed Apr 30 02:19:29 2008 found 24434594 singletons
Wed Apr 30 02:19:29 2008 current dataset: 132390244 relations and about 88294946 large ideals
Wed Apr 30 02:19:29 2008 commencing singleton removal, pass 5
Wed Apr 30 02:41:09 2008 relations with 0 large ideals: 0
Wed Apr 30 02:41:09 2008 relations with 1 large ideals: 742
Wed Apr 30 02:41:09 2008 relations with 2 large ideals: 23915
Wed Apr 30 02:41:09 2008 relations with 3 large ideals: 315754
Wed Apr 30 02:41:09 2008 relations with 4 large ideals: 2253955
Wed Apr 30 02:41:09 2008 relations with 5 large ideals: 9433948
Wed Apr 30 02:41:09 2008 relations with 6 large ideals: 23760197
Wed Apr 30 02:41:09 2008 relations with 7+ large ideals: 96601733
Wed Apr 30 02:41:09 2008 132390244 relations and about 107914977 large ideals
Wed Apr 30 02:41:09 2008 commencing singleton removal, pass 6
Wed Apr 30 03:02:51 2008 found 19388737 singletons
Wed Apr 30 03:02:51 2008 current dataset: 113001507 relations and about 87344686 large ideals
Wed Apr 30 03:02:51 2008 commencing singleton removal, pass 7
Wed Apr 30 03:21:45 2008 found 4530506 singletons
Wed Apr 30 03:21:45 2008 current dataset: 108471001 relations and about 82738277 large ideals
Wed Apr 30 03:21:45 2008 commencing singleton removal, pass 8
Wed Apr 30 03:40:00 2008 found 971921 singletons
Wed Apr 30 03:40:00 2008 current dataset: 107499080 relations and about 81762618 large ideals
Wed Apr 30 03:40:00 2008 commencing singleton removal, pass 9
Wed Apr 30 03:58:13 2008 found 198741 singletons
Wed Apr 30 03:58:13 2008 current dataset: 107300339 relations and about 81563729 large ideals
Wed Apr 30 03:58:13 2008 commencing singleton removal, final pass
Wed Apr 30 04:34:53 2008 memory use: 3808.2 MB
Wed Apr 30 04:34:56 2008 commencing in-memory singleton removal
Wed Apr 30 04:35:38 2008 begin with 107300339 relations and 92918933 unique ideals
Wed Apr 30 04:45:05 2008 reduce to 96734930 relations and 82148891 ideals in 16 passes
Wed Apr 30 04:45:05 2008 max relations containing the same ideal: 384
(clique removal)
Wed Apr 30 07:01:28 2008 removing 1529556 relations and 1129556 ideals in 400000 cliques
Wed Apr 30 07:01:30 2008 commencing in-memory singleton removal
Wed Apr 30 07:01:40 2008 begin with 31072254 relations and 31607946 unique ideals
Wed Apr 30 07:02:37 2008 reduce to 31021692 relations and 30427234 ideals in 6 passes
Wed Apr 30 07:02:37 2008 max relations containing the same ideal: 146
Wed Apr 30 07:03:23 2008 removing 249135 relations and 203084 ideals in 46051 cliques
Wed Apr 30 07:03:24 2008 commencing in-memory singleton removal
Wed Apr 30 07:03:35 2008 begin with 30772557 relations and 30427234 unique ideals
Wed Apr 30 07:04:12 2008 reduce to 30771559 relations and 30223150 ideals in 4 passes
Wed Apr 30 07:04:12 2008 max relations containing the same ideal: 145
Wed Apr 30 07:04:21 2008 filtering rational ideals above 750000
Wed Apr 30 07:04:21 2008 filtering algebraic ideals above 750000
Wed Apr 30 07:04:21 2008 need 120216 more relations than ideals
Wed Apr 30 07:04:21 2008 commencing singleton removal, final pass
Wed Apr 30 08:18:23 2008 keeping 73218132 ideals with weight <= 20, new excess is 9296364
Wed Apr 30 08:20:17 2008 memory use: 2639.6 MB
Wed Apr 30 08:20:18 2008 commencing in-memory singleton removal
Wed Apr 30 08:20:34 2008 begin with 96734931 relations and 73218132 unique ideals
Wed Apr 30 08:21:07 2008 reduce to 96734930 relations and 73218131 ideals in 2 passes
Wed Apr 30 08:21:07 2008 max relations containing the same ideal: 20
(more clique removal)
Wed Apr 30 09:26:13 2008 removing 1333448 relations and 993985 ideals in 339463 cliques
Wed Apr 30 09:26:14 2008 commencing in-memory singleton removal
Wed Apr 30 09:26:19 2008 begin with 35997998 relations and 26208200 unique ideals
Wed Apr 30 09:26:45 2008 reduce to 35964483 relations and 25180385 ideals in 5 passes
Wed Apr 30 09:26:45 2008 max relations containing the same ideal: 20
Wed Apr 30 09:27:14 2008 relations with 0 large ideals: 1594415
Wed Apr 30 09:27:14 2008 relations with 1 large ideals: 7302931
Wed Apr 30 09:27:14 2008 relations with 2 large ideals: 12706306
Wed Apr 30 09:27:14 2008 relations with 3 large ideals: 9939004
Wed Apr 30 09:27:14 2008 relations with 4 large ideals: 3708167
Wed Apr 30 09:27:14 2008 relations with 5 large ideals: 648403
Wed Apr 30 09:27:14 2008 relations with 6 large ideals: 61672
Wed Apr 30 09:27:14 2008 relations with 7+ large ideals: 3585
Wed Apr 30 09:27:14 2008 commencing 2-way merge
Wed Apr 30 09:27:49 2008 reduce to 24200819 relation sets and 13416721 unique ideals
Wed Apr 30 09:27:49 2008 commencing full merge
Wed Apr 30 09:31:27 2008 memory use: 1224.1 MB
Wed Apr 30 09:31:28 2008 found 12923421 cycles, need 11436921
Wed Apr 30 09:31:35 2008 weight of 11436921 cycles is about 743426050 (65.00/cycle)
Wed Apr 30 09:31:35 2008 distribution of cycle lengths:
Wed Apr 30 09:31:35 2008 1 relations: 1852171
Wed Apr 30 09:31:35 2008 2 relations: 1415558
Wed Apr 30 09:31:35 2008 3 relations: 1402932
Wed Apr 30 09:31:35 2008 4 relations: 1332850
Wed Apr 30 09:31:35 2008 5 relations: 1262651
Wed Apr 30 09:31:35 2008 6 relations: 1123342
Wed Apr 30 09:31:35 2008 7 relations: 983922
Wed Apr 30 09:31:35 2008 8 relations: 818904
Wed Apr 30 09:31:35 2008 9 relations: 659698
Wed Apr 30 09:31:35 2008 10+ relations: 584893
Wed Apr 30 09:31:35 2008 heaviest cycle: 12 relations
Wed Apr 30 09:31:36 2008 commencing cycle optimization
Wed Apr 30 09:32:04 2008 start with 52607046 relations
Wed Apr 30 09:33:45 2008 pruned 1197440 relations
Wed Apr 30 09:33:46 2008 memory use: 1822.9 MB
Wed Apr 30 09:33:46 2008 distribution of cycle lengths:
Wed Apr 30 09:33:46 2008 1 relations: 1852171
Wed Apr 30 09:33:46 2008 2 relations: 1448894
Wed Apr 30 09:33:46 2008 3 relations: 1454488
Wed Apr 30 09:33:46 2008 4 relations: 1370864
Wed Apr 30 09:33:46 2008 5 relations: 1305864
Wed Apr 30 09:33:46 2008 6 relations: 1153396
Wed Apr 30 09:33:46 2008 7 relations: 1000698
Wed Apr 30 09:33:46 2008 8 relations: 806218
Wed Apr 30 09:33:46 2008 9 relations: 605076
Wed Apr 30 09:33:46 2008 10+ relations: 439252
Wed Apr 30 09:33:46 2008 heaviest cycle: 12 relations
Wed Apr 30 09:34:11 2008 elapsed time 09:46:11
Wed Apr 30 18:27:33 2008
Wed Apr 30 18:27:33 2008
Wed Apr 30 18:27:33 2008 Msieve v. 1.34
Wed Apr 30 18:27:33 2008 random seeds: aed73ff8 776b3e7d
Wed Apr 30 18:27:33 2008 factoring 2652879528384736294387787089866884113161756949676609780113021980279955578028580515829763316598420245173034168388765124717208315443806148182904105317960270313646866242717807445467423472021744641 (193 digits)
Wed Apr 30 18:27:36 2008 no P-1/P+1/ECM available, skipping
Wed Apr 30 18:27:36 2008 commencing number field sieve (193-digit input)
Wed Apr 30 18:27:36 2008 R0: 35917545547686059365808220080151141317043
Wed Apr 30 18:27:36 2008 R1: -1
Wed Apr 30 18:27:36 2008 A0: 1
Wed Apr 30 18:27:36 2008 A1: 0
Wed Apr 30 18:27:36 2008 A2: 0
Wed Apr 30 18:27:36 2008 A3: 0
Wed Apr 30 18:27:36 2008 A4: 0
Wed Apr 30 18:27:36 2008 A5: 0
Wed Apr 30 18:27:36 2008 A6: 9
Wed Apr 30 18:27:36 2008 size score = 8.379415e-12, Murphy alpha = 1.425790, combined = 5.575653e-12
Wed Apr 30 18:27:36 2008
Wed Apr 30 18:27:36 2008 commencing linear algebra
Wed Apr 30 18:27:39 2008 read 11436921 cycles
Wed Apr 30 18:29:28 2008 cycles contain 31057959 unique relations
Wed Apr 30 18:36:05 2008 read 31057959 relations
Wed Apr 30 18:37:25 2008 using 32 quadratic characters above 2147480850
Wed Apr 30 18:43:03 2008 building initial matrix
Wed Apr 30 18:56:01 2008 memory use: 3942.0 MB
Wed Apr 30 18:56:11 2008 read 11436921 cycles
Wed Apr 30 18:56:35 2008 matrix is 11435826 x 11436921 (3204.8 MB) with weight 1001600646 (87.58/col)
Wed Apr 30 18:56:35 2008 sparse part has weight 714320576 (62.46/col)
Wed Apr 30 19:01:47 2008 filtering completed in 3 passes
Wed Apr 30 19:01:51 2008 matrix is 11400059 x 11400259 (3199.3 MB) with weight 999652442 (87.69/col)
Wed Apr 30 19:01:51 2008 sparse part has weight 713277612 (62.57/col)
Wed Apr 30 19:04:34 2008 read 11400259 cycles
Wed Apr 30 19:04:50 2008 matrix is 11400059 x 11400259 (3199.3 MB) with weight 999652442 (87.69/col)
Wed Apr 30 19:04:50 2008 sparse part has weight 713277612 (62.57/col)
Wed Apr 30 19:04:51 2008 saving the first 48 matrix rows for later
Wed Apr 30 19:04:57 2008 matrix is 11400011 x 11400259 (3083.8 MB) with weight 762539620 (66.89/col)
Wed Apr 30 19:04:57 2008 sparse part has weight 694386289 (60.91/col)
Wed Apr 30 19:04:57 2008 matrix includes 64 packed rows
Wed Apr 30 19:04:57 2008 using block size 65536 for processor cache size 4096 kB
Wed Apr 30 19:06:19 2008 commencing Lanczos iteration
Wed Apr 30 19:06:19 2008 memory use: 3047.6 MB
[/code]

and memory usage by msieve was fairly steady at 3771MB, so that would have just fitted on the 4GB machine. I'll be interested to see how the final numbers change with the ten or so million new relations I'm currently downloading.

Final matrix for 3+512
 

[code]
found 7795849 duplicates and 183336747 unique relations
memory use: 1911.0 MB
ignoring smallest 7108914 rational and 7107522 algebraic ideals
filtering rational ideals above 124977152
filtering algebraic ideals above 124977152
need 21324654 more relations than ideals
commencing singleton removal, pass 1
relations with 0 large ideals: 4720680
relations with 1 large ideals: 26532618
relations with 2 large ideals: 60196322
relations with 3 large ideals: 64203955
relations with 4 large ideals: 27674969
relations with 5 large ideals: 8203
relations with 6 large ideals: 0
relations with 7+ large ideals: 0
183336747 relations and about 92964614 large ideals
commencing singleton removal, pass 2
found 16723680 singletons
current dataset: 166613067 relations and about 75630287 large ideals
commencing singleton removal, pass 3
relations with 0 large ideals: 4720680
relations with 1 large ideals: 25504572
relations with 2 large ideals: 55639049
relations with 3 large ideals: 57071988
relations with 4 large ideals: 23669787
relations with 5 large ideals: 6991
relations with 6 large ideals: 0
relations with 7+ large ideals: 0
166613067 relations and about 107615586 large ideals
commencing singleton removal, pass 4
found 24157797 singletons
current dataset: 142455270 relations and about 82004924 large ideals
commencing singleton removal, pass 5
relations with 0 large ideals: 4720680
relations with 1 large ideals: 23872815
relations with 2 large ideals: 48775066
relations with 3 large ideals: 46864018
relations with 4 large ideals: 18217312
relations with 5 large ideals: 5379
relations with 6 large ideals: 0
relations with 7+ large ideals: 0
142455270 relations and about 99364914 large ideals
commencing singleton removal, pass 6
found 18002328 singletons
current dataset: 124452942 relations and about 80432277 large ideals
commencing singleton removal, pass 7
found 3972915 singletons
current dataset: 120480027 relations and about 76405418 large ideals
commencing singleton removal, pass 8
found 793186 singletons
current dataset: 119686841 relations and about 75609909 large ideals
commencing singleton removal, pass 9
found 148752 singletons
current dataset: 119538089 relations and about 75461071 large ideals
commencing singleton removal, final pass
memory use: 1948.8 MB
commencing in-memory singleton removal
begin with 119538089 relations and 85069326 unique ideals
reduce to 111164660 relations and 76572690 ideals in 13 passes
max relations containing the same ideal: 52
(clique removal)
commencing in-memory singleton removal
begin with 52911835 relations and 31837518 unique ideals
reduce to 52911003 relations and 31586348 ideals in 4 passes
max relations containing the same ideal: 31
filtering rational ideals above 750000
filtering algebraic ideals above 750000
need 120216 more relations than ideals
commencing singleton removal, final pass
keeping 80668853 ideals with weight <= 20, new excess is 10119748
memory use: 2671.2 MB
commencing in-memory singleton removal
begin with 111164660 relations and 80668853 unique ideals
reduce to 111156501 relations and 80660693 ideals in 8 passes
max relations containing the same ideal: 20
(clique removal)
commencing in-memory singleton removal
begin with 33196574 relations and 22370231 unique ideals
reduce to 33162215 relations and 21422807 ideals in 5 passes
max relations containing the same ideal: 17
relations with 0 large ideals: 2123367
relations with 1 large ideals: 8561800
relations with 2 large ideals: 12486331
relations with 3 large ideals: 7673775
relations with 4 large ideals: 2077904
relations with 5 large ideals: 225955
relations with 6 large ideals: 12656
relations with 7+ large ideals: 427
commencing 2-way merge
reduce to 22959819 relation sets and 11220411 unique ideals
commencing full merge
memory use: 1052.0 MB
found 12504356 cycles, need 10888611
weight of 10888611 cycles is about 707963521 (65.02/cycle)
distribution of cycle lengths:
1 relations: 2159899
2 relations: 1303681
3 relations: 1228402
4 relations: 1152853
5 relations: 1095856
6 relations: 994754
7 relations: 883124
8 relations: 755936
9 relations: 616168
10+ relations: 697938
heaviest cycle: 12 relations
commencing cycle optimization
start with 49500473 relations
pruned 1522481 relations
memory use: 1660.5 MB
distribution of cycle lengths:
1 relations: 2159899
2 relations: 1341861
3 relations: 1280474
4 relations: 1197979
5 relations: 1153379
6 relations: 1039012
7 relations: 914211
8 relations: 747326
9 relations: 561539
10+ relations: 492931
heaviest cycle: 12 relations
elapsed time 08:57:36
[/code]

So 10.6 million relations have gained us 550 thousand dimensions, or 6.2% more unique relations have saved us 4.8% of the matrix dimensions.

It's quite a large matrix but should fit in 4GB; there's a small problem of whether the matrix-build is memory-local enough to run swapping over NFS, since I know it will take >4GB and the machine I'm using has a 2G USB stick as local disc. I'll start the linalg on Saturday (fibonacci(1021) is running on that machine at the moment), it will probably take two weeks.

[quote=fivemack;133008]

So 10.6 million relations have gained us 550 thousand dimensions, or 6.2% more unique relations have saved us 4.8% of the matrix dimensions.

I'll start the linalg on Saturday (fibonacci(1021) is running on that machine at the moment), it will probably take two weeks.[/quote]

It took about 8 hours to get those 10.6M relations (well, it took 8 hours for my 7M, and I'm guessing about that long for the rest, working in parallel).

2 weeks = 336 hrs = 1209600 seconds or ~ 0.111 sec/dimension.

So reducing 550000 dimensions saved ~ 17 hours, less 8 hours of extra sieving, according to this napkin math :smile:.

It should be even better than that. The LA time is super-linear in the dimensionality of the matrix. The number of iterations is linear, but each iteration should be faster on the smaller matrix.

The linear algebra has started:

[code]
Sun May 11 02:39:47 2008 matrix is 10856877 x 10857125 (2895.2 MB) with weight 714095503 (65.77/col)
Sun May 11 02:39:47 2008 sparse part has weight 650401084 (59.91/col)
Sun May 11 02:39:47 2008 matrix includes 64 packed rows
Sun May 11 02:39:47 2008 using block size 65536 for processor cache size 4096 kB
Sun May 11 02:40:56 2008 commencing Lanczos iteration (4 threads)
Sun May 11 02:40:56 2008 memory use: 3112.7 MB
[/code]

ETA is afternoon of May 29th; whilst it said 'memory use: 3112.7MB', top says
[code]
7435 nfsslave 25 0 3574m 3.3g 440 R 341 87.7 3976:19 msieve
[/code]

Anyway, it fits in 4GB which was the important issue.

[QUOTE=fivemack;133234]The linear algebra has started:

[code]
Sun May 11 02:39:47 2008 matrix is 10856877 x 10857125 (2895.2 MB) with weight 714095503 (65.77/col)
Sun May 11 02:39:47 2008 sparse part has weight 650401084 (59.91/col)
Sun May 11 02:39:47 2008 matrix includes 64 packed rows
Sun May 11 02:39:47 2008 using block size 65536 for processor cache size 4096 kB
Sun May 11 02:40:56 2008 commencing Lanczos iteration (4 threads)
Sun May 11 02:40:56 2008 memory use: 3112.7 MB
[/code]

ETA is afternoon of May 29th; whilst it said 'memory use: 3112.7MB', top says
[code]
7435 nfsslave 25 0 3574m 3.3g 440 R 341 87.7 3976:19 msieve
[/code]

Anyway, it fits in 4GB which was the important issue.[/QUOTE]
The disparity between estimated and actual memory use is actually smaller than I've seen posted elsewhere; for comparison the actual memory use of the filtering step tends to be 30-50% larger than what the library estimates. Instead of measuring the size of data structures, I could instead use library functions like mallinfo(), but all of these assume 31-bit values for memory used.

Otherwise, the final matrix density looks dangerously low; I should change TARGET_DENSITY from 65.0 to 70.0 in the future, to force the final matrix to be more dense.

Not an ECM miss!
 

[code]
Sun May 11 23:47:01 2008 commencing Lanczos iteration (4 threads)
Sun May 11 23:47:01 2008 memory use: 3112.7 MB
Sun May 11 23:47:19 2008 restarting at iteration 7909 (dim = 500081)
Thu May 29 15:11:11 2008 lanczos halted after 171698 iterations (dim = 10856872)
Thu May 29 15:11:52 2008 recovered 50 nontrivial dependencies
Thu May 29 15:11:55 2008 elapsed time 423:28:20
Thu May 29 19:09:18 2008 Msieve v. 1.34
Thu May 29 19:09:19 2008 commencing square root phase
Thu May 29 19:09:19 2008 reading relations for dependency 1
Thu May 29 19:09:31 2008 read 5427551 cycles
Thu May 29 19:10:06 2008 cycles contain 17096763 unique relations
Thu May 29 19:15:57 2008 read 17096763 relations
Thu May 29 19:20:03 2008 multiplying 23949492 relations
Thu May 29 21:21:20 2008 multiply complete, coefficients have about 690.79 million bits
Thu May 29 21:21:35 2008 initial square root is modulo 1575811
Thu May 29 23:59:17 2008 prp93 factor: 185203545384014444998415700339182963094565346115682981302539679248192554448695865898272140289
Thu May 29 23:59:17 2008 prp101 factor: 14324129286424100231861565705311821806023066083407911748417199121054089089998098987789407767132602369
Thu May 29 23:59:17 2008 elapsed time 04:49:59
[/code]

Thanks for all the cycles!

[QUOTE=fivemack;134746]not an ECM miss[/QUOTE]

And NOT an p-1 or p+1 miss too, some ECM curves at the 15- and 20 digit levels show that both factors are waaaay out of p+/-1 range.

[quote=Andi47;134767]And NOT an p-1 or p+1 miss too, some ECM curves at the 15- and 20 digit levels show that both factors are waaaay out of p+/-1 range.[/quote]

Indeed:
[code]

prp93 - 1 = 2^10 * 10935391 * 873411622106606511242977261100967248293 * 18936340619807636319594684484400404592181649
prp93 + 1 = 2 * 3 * 5 * 13 * 661 * 12940947333474585331284139 * 8378869400326912691301842743 * 6625699555011851410351750036873963

prp101 - 1 = 2^15 * 3^7 * 2153 * 3691 * 121727 * 206630544613448030672025489880296233031839828693270211360359233883363407408743913
prp101 + 1 = 2 * 5 * 239049199913 * 5992126010728021621153697446264425308377152528306321229288237982195655176636574810316549

[/code]

Thanks, fivemack, for organizing this effort!