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 2010-08-17, 02:09 #1 frmky     Jul 2003 So Cal 7FB16 Posts OddPerfect enthusiasts & others: ECM help needed! NFS@Home is working its way up in difficulty toward a kilobit SNFS. We're at 285 digits now, and in about 1-2 months we will start a 290 digit number. sigma(3^606) = 3,607- is a very attractive number since it's simultaneously an OddPerfect roadblock, Cunningham 5th hole once the 3- extension is added (and 3,563- is finished, which will happen shortly), and a number with no known nontrivial factors. We would appreciate any help the OP community and others can provide. For now, the number needs more ECM. Currently a bit over 1*t55 has been completed, so it needs curves with B1 = 26e7. The easiest way is to create a file containing the line (3^607-1)/2 then run the command ecm -c 10 26e7 < file.txt Adjust 10 to the number of curves you wish to run. Just report the number of curves you have completed in this thread, and thanks in advance for any help you can provide! All curves are included in the ECM Server at oddperfect.no-ip.com:8201 Code: Post# Curves 4 10 20 40 28 4 36 1 41 15 46 224 49 3100 included in #72 53 320 57 3 72 3508 included in ECM Server 73 3393 new in ECM Server 74 240 75 10 76 960 77 6703 87 883 89 4594 Including directly reported curves, the ECM Server stands at 23785 including lower ECM curves (13875@43e6 & 18240@11e7), this is 4.90 t55 or 0.96 t60 Last fiddled with by wblipp on 2010-08-27 at 00:50 Reason: Update Progress
2010-08-17, 06:08   #2
Andi47

Oct 2004
Austria

7·353 Posts

Quote:
 Originally Posted by frmky The easiest way is to create a file containing the line (3^607-1)/2 then run the command ecm -nn -c 10 26e7 < file.txt Adjust 10 to the number of curves you wish to run. Just report the number of curves you have completed in this thread, and thanks in advance for any help you can provide!
I would suggest a command line like

ecm -nn -c 10 26e7 <file.txt >>outputfile.out

with the -nn flag, ecm will run on lowest priority.

">>outputfile.out" redirects the output to an outputfile and thus prevents from data loss when a factor is found and the command line window (or bash window) is accidently closed (or the computer crashes for some reason).

If the PC is short on RAM, the command line flag -maxmem <number of MB to use> can be used. For example, -maxmem 500 uses not more than 500 MB RAM.

I will run a fistful of curves until my next GNFS (from aliquot sequence 10212) takes my ressources for a while.

Last fiddled with by Andi47 on 2010-08-17 at 06:12

2010-08-17, 06:20   #3
mdettweiler
A Sunny Moo

Aug 2007
USA (GMT-5)

11000011000012 Posts

Quote:
 Originally Posted by Andi47 I would suggest a command line like ecm -nn -c 10 26e7 >outputfile.out with the -nn flag, ecm will run on lowest priority. ">>outputfile.out" redirects the output to an outputfile and thus prevents from data loss when a factor is found and the command line window (or bash window) is accidently closed (or the computer crashes for some reason).
Even better, if you're on Linux (or Windows w/Cygwin):

./ecm -nn -c 10 26e7 < file.txt | tee -a outputfile.out

That will send the screen output both to the file outputfile.out and to the screen, which is nicer for checking progress along the way.

Those on Windows without Cygwin can probably get tee in UnxUtils; just place tee.exe in the same directory as ecm.exe (or somewhere on your path, if you prefer).

 2010-08-17, 07:26 #4 debrouxl     Sep 2009 97710 Posts Another way to output both to a file and to the screen: ecm -nn -c 10 26e7 < file.txt >> outputfile.out &; tail -f outputfile.out or echo "(3^607-1)/2" | ecm -nn -c 10 26e7 >> outputfile.out &; tail -f outputfile.out (CTRL + C to end) I'm running 10 curves, 1 done so far without finding a factor. I won't repost if these curves run to completion without yielding a factor, so as not to clutter the topic
 2010-08-17, 08:30 #5 Andi47     Oct 2004 Austria 7×353 Posts P-1: B1=1e9, B2=1e14, no factor.
2010-08-17, 10:03   #6
Andi47

Oct 2004
Austria

9A716 Posts

Quote:
 Originally Posted by Andi47 I will run a fistful of curves until my next GNFS (from aliquot sequence 10212) takes my ressources for a while.
cancelled / crashed, no single curve finished.

In a windoze environment it seems that it is absolutely necessary to specify -maxmem 1800 (or smaller), even if you have plenty of free memory and you are using Win 64 bit and a 64 bit ECM binary.

(ECM crashed when it tried to use more than ~1.8 GB (or 2 GB??) RAM, and I am pretty sure to have downloaded the 64 bit binary of ecm-6.2.3 (how can I check if this is indeed a 64 bit binary?))

Last fiddled with by Andi47 on 2010-08-17 at 10:05

2010-08-17, 11:19   #7
10metreh

Nov 2008

2·33·43 Posts

Quote:
 Originally Posted by Andi47 (ECM crashed when it tried to use more than ~1.8 GB (or 2 GB??) RAM, and I am pretty sure to have downloaded the 64 bit binary of ecm-6.2.3 (how can I check if this is indeed a 64 bit binary?))
Run it (on something smaller so that it will run without crashing), and look in Task Manager. If it shows up as "ecm.exe *32" then it is 32-bit; if it is just "ecm.exe" then it is 64-bit.

2010-08-17, 11:23   #8
Andi47

Oct 2004
Austria

46478 Posts

Quote:
 Originally Posted by 10metreh Run it (on something smaller so that it will run without crashing), and look in Task Manager. If it shows up as "ecm.exe *32" then it is 32-bit; if it is just "ecm.exe" then it is 64-bit.
Thanks. And oops, it seems that something went wrong when I downloaded the binary (maybe I copied it into the wrong directory), as it says that the binary I'm using is 32 bit.

Edit: Just downloaded the 64 bit binary and started a large p-1: it is running happily with a memory useage of 3.3 GB.

Last fiddled with by Andi47 on 2010-08-17 at 12:11

 2010-08-17, 12:22 #9 em99010pepe     Sep 2004 54168 Posts Anyone here wants to set up an ecmserver for this number?
2010-08-17, 12:28   #10
R.D. Silverman

Nov 2003

26·113 Posts

Quote:
 Originally Posted by frmky NFS@Home is working its way up in difficulty toward a kilobit SNFS. We're at 285 digits now, and in about 1-2 months we will start a 290 digit number. sigma(3^606) = 3,607- is a very attractive number since it's simultaneously an OddPerfect roadblock, Cunningham 5th hole once the 3- extension is added (and 3,563- is finished, which will happen shortly), and a number with no known nontrivial factors. We would appreciate any help the OP community and others can provide. For now, the number needs more ECM. Currently a bit over 1*t55 has been completed, so it needs curves with B1 = 26e7. The easiest way is to create a file containing the line (3^607-1)/2 then run the command ecm -c 10 26e7 < file.txt Adjust 10 to the number of curves you wish to run. Just report the number of curves you have completed in this thread, and thanks in advance for any help you can provide!
My personal opinion is that doing a number from the extensions, when
the extensions still have not been officially added to the table is
ridiculous

There are many other suitable numbers, still undone, from the 1st printed
edition of the book. Let's work on finishing them.

2010-08-17, 12:39   #11
Andi47

Oct 2004
Austria

7·353 Posts

Quote:
 Originally Posted by Andi47 P-1: B1=1e9, B2=1e14, no factor.
extended B2 to 1e15, still no factor.

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