20101112, 22:23  #1 
(loop (#_fork))
Feb 2006
Cambridge, England
2·7·461 Posts 
Let's do another nice big GNFS job!
Various people  bdodson, batalov, jrk  have done a GPUassisted polynomial search for the 187digit cofactor of 2^956+1, and we have a decent polynomial, which should produce a matrix no harder than SNFS matrices that I've already done, in no more than ten to fifteen CPUyears of sieving.
This is a 16e job (with three large primes), so you will want about a gigabyte per core/thread  15e doesn't seem to give enough yield at the larger Q values. Start off with Q=20 to 160 million. Won't be done by Christmas, but we could probably get the relations in by the end of winter and factors by Easter. Polynomial: Code:
n: 1332203900608590809938480645779084229713406802212647383719972524986911760145731133592887032687895490700549453758482415452796437240091528083264268919532584204888670812466960924609380670193 type: gnfs # norm 2.589534e18 alpha 8.321781 e 2.991e14 rroots 5 skew: 320811150.54 c0: 405063155184101117008321502924944026097244672704 c1: 3339583019941934259279259002396544515176 c2: 47189249406761789351128506210198 c3: 265660627688613695069141 c4: 586429385543294 c5: 182280 Y0: 1488559874631410107110585286834796715 Y1: 149978515624994424157 alim: 150000000 rlim: 150000000 lpba: 32 lpbr: 31 mfba: 94 mfbr: 62 alambda: 3.6 rlambda: 2.6 gnfslasieve4I16e v M 1 a t.poly f <starting value> c 10000 This is not a quick job, each relation takes about one CPUsecond on a K8/2500 using the 64bit assembly siever, and we need about four hundred million of them. The yield is about 3.5 million relations per million Q (less for smaller Q), so a range of one million will take about four to five weeks on a single core; take short ranges unless you have multicore machines, and you might wish to consider other projects if your machine is not 64bit. Upload by ftp, host ssh.fivemack.org, directory 2+956, as .gz Reservations: gimarel 20M21M done ET_ 21M22M done gimarel 22M25M done fivemack 25M26M done bsquared 26M40M done fivemack 40M43M done andi47 43M44M done gimarel 44M50M done bsquared 50M55M done fivemack 55M60M done bdodson 60M67M done batalov 67M68M done fivemack 68M70M done bdodson 70M130M done bsquared 130M134M done batalov 134M135M done bdodson 135M150M done fivemack 150M151M done bdodson 151M160M done bdodson 160M180M done bdodson 180M190M done Results: Code:
20M 21M 17/11 2250928 gimarel 21M 22M 15/12 2300458 ET_ 22M 25M 30/11 7071161 gimarel 25M 26M 25/11 2478091 fivemack 26M 40M 06/12 37088160 bsquared 40M 43M 03/12 8924404 fivemack 43M 44M 19/12 3014307 andi47 44M 50M 22/12 17975701 gimarel 50M 55M 14/12 15809882 bsquared 55M 60M 23/12 16096105 fivemack 60M 67M 06/01 22967376 bdodson 67M 68M 31/12 3283937 batalov 68M 70M 08/01 6600716 fivemack 70M 75M 25/12 16624144 bdodson 75M 80M 25/12 16661056 bdodson 80M 85M 22/12 16757155 bdodson 85M 90M 22/12 16789593 bdodson 90M 95M 24/12 16839477 bdodson 95M100M 24/12 16746582 bdodson 100M105M 17/12 16849538 bdodson 105M110M 17/12 16858220 bdodson 110M115M 19/12 16682276 bdodson 115M120M 19/12 16718242 bdodson 120M125M 20/12 16678274 bdodson 125M130M 20/12 16619360 bdodson 130M134M 27/12 13226962 bsquared 134M135M 27/11 3315231 batalov 135M150M 01/12 49267416 bdodson 150M151M 20/11 3263769 fivemack 151M160M 03/12 29117682 bdodson 160M165M 05/01 16012568 bdodson 165M170M 05/01 15878307 bdodson 170M175M 08/01 15727747 bdodson 175M180M 08/01 15569140 bdodson 180M185M 10/01 15507504 bdodson 185M190M 10/01 15374119 bdodson Last fiddled with by fivemack on 20110110 at 09:24 Reason: and it's done 
20101113, 08:05  #2 
Oct 2004
Austria
2·17·73 Posts 
What exactly does the "M 1" in the command line do?
(I guess, "v" stands for "verbouse"?) 
20101113, 14:46  #4 
Banned
"Luigi"
Aug 2002
Team Italia
1001011111001_{2} Posts 
I'd like to offer some help. I have an i5750 @ 2.66 GHz and 8 GB of memory on Ubuntu 64bit, but I'm unsure if I got the correct executable (1055887 bytes).
1  Is it the right one or is there a link where I can get it? 2  the t.poly is the polynomial presented in the first post, correct? 3  What does the c switch mean? I'll try first with 1 core, then (when other jobs will finish) I'll add some more power. 4  Should I insert 21000000 on the <starting value> position? 5  Should I restart the computer, what is the correct procedure to maintain the work done? Thank you! Luigi 
20101113, 16:58  #5 
Oct 2004
Austria
9B2_{16} Posts 
1.  have not checked if it's the right one....
2.  yes 3.  this is the switch to adjust the size of the range. When you start at 21M and type "c 10000", then it runs up to 21010000 4.  yes (if you want to start at 21M) 5.  just add "R" to the command line you have typed the first time. In this case GGNFS reads the output file, restarts the job where it has been interrupted and runs up to your desired end of the range. 
20101113, 17:28  #6  
Banned
"Luigi"
Aug 2002
Team Italia
1001011111001_{2} Posts 
Quote:
I will start 21M22M as soon as question 1 will get an answer. Luigi 

20101113, 18:35  #7  
(loop (#_fork))
Feb 2006
Cambridge, England
2·7·461 Posts 
Quote:
I would just run yours on a range of 1000 or so; if you get about 3000 relations and a timeperrelation of about 0.7 seconds it's likely to be right. Tom Last fiddled with by fivemack on 20101113 at 18:35 

20101113, 19:36  #8  
Banned
"Luigi"
Aug 2002
Team Italia
12F9_{16} Posts 
Quote:
Hints on where to get the good one? Luigi 

20101114, 00:05  #9 
"Serge"
Mar 2008
Phi(4,2^7658614+1)/2
10053_{10} Posts 
I get 0.55s/rel  but that's a K10 at 3640MHz (and using L1_BITS=16).
Use a L1_BITS=15 binary for Intel CPUs (they all have only 32Kb cache). It also depends on the range. Tom probably has the data from sims  some graphs (just like those in earlier projects) could be helpful for participants to adjust their expectations. 
20101114, 11:42  #10 
(loop (#_fork))
Feb 2006
Cambridge, England
2·7·461 Posts 
ET_: 0.85s/rel probably isn't too bad, but you might want to try
ftp://ssh.fivemack.org/gnfslasieve4I16e and see if it's any faster for you. 
20101114, 11:56  #11  
Banned
"Luigi"
Aug 2002
Team Italia
3×1,619 Posts 
Quote:
May I start working on with my executable and eventually exchange it with a newer version during the run? Luigi Last fiddled with by ET_ on 20101114 at 11:57 

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