Reserved for MF - Sequence 4788

[Andi47]

After these factors...

Originally Posted by fivemack

Sat Dec 12 11:42:54 2009  commencing Lanczos iteration (4 threads)
Sat Dec 12 11:42:54 2009  memory use: 2078.2 MB
Wed Dec 16 16:41:13 2009  lanczos halted after 105593 iterations (dim = 6676993)
Wed Dec 16 16:41:27 2009  recovered 26 nontrivial dependencies
Wed Dec 16 16:41:29 2009  BLanczosTime: 364766
Wed Dec 16 16:41:29 2009  
Wed Dec 16 16:41:29 2009  commencing square root phase
Wed Dec 16 16:41:29 2009  reading relations for dependency 1
Wed Dec 16 16:41:30 2009  read 3336056 cycles
Wed Dec 16 16:41:39 2009  cycles contain 9688282 unique relations
Wed Dec 16 16:45:43 2009  read 9688282 relations
Wed Dec 16 16:47:15 2009  multiplying 9688282 relations
Wed Dec 16 17:19:03 2009  multiply complete, coefficients have about 510.55 million bits
Wed Dec 16 17:19:11 2009  initial square root is modulo 1448310641
Wed Dec 16 18:24:08 2009  sqrtTime: 6159
Wed Dec 16 18:24:08 2009  prp67 factor: 3080910905336815970632301939361370294511667581515422926255876218391
Wed Dec 16 18:24:08 2009  prp94 factor: 7243015684383815871382996543105076138574662378185857800256367590422019476790807257932033039189
Wed Dec 16 18:24:08 2009  elapsed time 104:53:07

we now have a c141 in iteration 2487.

150 curves at B1=3e6 and counting...

[henryzz]

i have also done 100 @3e6

[fivemack]

I've set 20,000 @ 1e7 going, should have some kind of result by Monday.

[fivemack]

ECM not looking terribly promising; I'll do the GNFS for this one, it'll easily be done by Christmas.

[Andi47]

Originally Posted by fivemack

ECM not looking terribly promising; I'll do the GNFS for this one, it'll easily be done by Christmas.

Have you done P-1? I would suggest B1=1e9, B2=1e15 before GNFSing (~ 1-2 hours on a c2d~2GHz, 64 bit-system; make sure to specify the -maxmem flag according to your free RAM.)

[henryzz]

Originally Posted by Andi47

Have you done P-1? I would suggest B1=1e9, B2=1e15 before GNFSing (~ 1-2 hours on a c2d~2GHz, 64 bit-system; make sure to specify the -maxmem flag according to your free RAM.)

if no-one has done it i would like to do it
cant do that and p+1 quickly though

[mdettweiler]

Originally Posted by henryzz

if no-one has done it i would like to do it
cant do that and p+1 quickly though

What P+1 bounds would be best? I could do that if nobody else wants to.

[Andi47]

Originally Posted by mdettweiler

What P+1 bounds would be best? I could do that if nobody else wants to.

Depends on your RAM and your system speed. 3 runs at B1=1e9, B2=1e15 should be doable overnight on a C2D, 2 GHz, 2 GB RAM (64 bit). If you have less than 2 GB RAM, better B2=5e13.

(if you want to spend just an hour or two, do B1=1e8, B2=1e13)

Edit: I would have done it if I had a CPU available (i.e. not busy with something else) *now*. I had planned to do p+/-1 tomorrow (GMT+1), but as GNFS is about to start, it should be better run today.

[mdettweiler]

Originally Posted by Andi47

Depends on your RAM and your system speed. 3 runs at B1=1e9, B2=1e15 should be doable overnight on a C2D, 2 GHz, 2 GB RAM (64 bit). If you have less than 2 GB RAM, better B2=5e13.

(if you want to spend just an hour or two, do B1=1e8, B2=1e13)

Edit: I would have done it if I had a CPU available (i.e. not busy with something else) *now*. I had planned to do p+/-1 tomorrow (GMT+1), but as GNFS is about to start, it should be better run today.

Okay, I've started a run with 3 curves at B1=1e9, B2=5e13. The machine running it is a C2D @ 2.2Ghz with 1.2GB of RAM allocated (I have 2GB, but want to leave a bit of headroom). There's a bit of thermal throttling in play so it might take a little longer than normal, but I expect it will be done by tomorrow morning (EST).

[henryzz]

i got bored and started the p-1 anyway
it is finished and only took 20 minutes
would it help if i took 1 of the p+1s off you medettweiler? i should be able to do it quite quickly

[mdettweiler]

Originally Posted by henryzz

i got bored and started the p-1 anyway
it is finished and only took 20 minutes
would it help if i took 1 of the p+1s off you medettweiler? i should be able to do it quite quickly

Go ahead and do all the P+1's if you like. It seems there was a problem when I tried to do it:

$ echo "59066643232529177994432826503455645911804472822311052434786614015983698
8457920218063108883526241212940105498096765045722201184707349955127817" | ./ecm
.exe 1e9 5e13 -c 3 -pp1 -maxmem 1228 | tee -a pp1-4788.txt
GMP-ECM 6.2.3 [powered by GMP 4.2.1_MPIR_1.1.1] [ECM]
Input number is 5906664323252917799443282650345564591180447282231105243478661401
59836988457920218063108883526241212940105498096765045722201184707349955127817 (1
41 digits)
Using B1=1000000000, B2=51984971408388, polynomial Dickson(30), sigma=2038232620
 
Step 1 took 14294375ms
GNU MP: Cannot allocate memory (size=64)
 
This application has requested the Runtime to terminate it in an unusual way.
Please contact the application's support team for more information.

The machine has about 1400-1600 MB of free memory, on average, according to Task Manager, so I figured 1.2GB should be quite safe. It would seem that either that was too much, or there was something else that caused it to have a problem allocating memory. Does anyone know what might have caused this?