20211222, 18:42  #991 
May 2003
100100011_{2} Posts 
NFS on 2993654893573563190431934488554477666944329734311027266211 4
from the t2200 file Doing ECM to 1000 curves on composites in the t2200 file, starting from the bottom. Already found one factor. Last fiddled with by ThomRuley on 20211222 at 18:43 
20211223, 07:56  #992  
Oct 2007
Manchester, UK
2×683 Posts 
What size factors are you looking for with ECM? I already did some work on this file:
Quote:


20211223, 11:05  #993  
Just call me Henry
"David"
Sep 2007
Liverpool (GMT/BST)
2·3^{2}·331 Posts 
Quote:
Many of these numbers will have had further ecm as part of https://mersenneforum.org/showpost.p...&postcount=958 Also gpu ecm is no longer limited to a max of 2^1018. 

20211223, 14:07  #994  
May 2003
100100011_{2} Posts 
Quote:
Like I had mentioned earlier, I'm doing ECM on the largest numbers as those composites are simply too large for anything else. Are you saying it would be better to run more curves on fewer composites or would it be better to start with going to say, 10^30 on a lot of the larger composites? I'm open to suggestions, but it would definitely be a benefit if there were some way to track what has and hasn't been done. 

20211225, 13:20  #995  
Oct 2007
Manchester, UK
2×683 Posts 
Quote:
Quote:
Last fiddled with by lavalamp on 20211225 at 13:20 

20211225, 18:29  #996 
May 2003
3×97 Posts 
EDIT  duplicate
Last fiddled with by ThomRuley on 20211225 at 18:32 
20211225, 18:31  #997  
May 2003
123_{16} Posts 
Quote:


20211225, 18:38  #998  
"Curtis"
Feb 2005
Riverside, CA
2^{2}·1,291 Posts 
Quote:


20211225, 20:05  #999 
May 2003
3×97 Posts 
That sounds great. How do I start using gmpecm?

20211226, 07:14  #1000 
"Curtis"
Feb 2005
Riverside, CA
2^{2}×1,291 Posts 
Once you get the program (I see you asked about that in another thread), open a terminal window in the folder where you have the program.
ecm h will give you the list of options you can pass to the program. The way I run it (there are many methods for handling inputs and outputs) is to make a text file with a list of a few inputs, and invoke ecm like so: ecm c 300 25e4 <inputfile1.txt >results1.txt This way, the results of the curves are recorded to a file rather than printed to screen. c tells ECM how many curves to run, and 25e4 is my sample B1 value (corresponding to curves at T30 level you might choose to start at 1e6 for T35 instead). If a factor is found but the cofactor is composite, ECM will continue to finish out the curves trying to crack the cofactor. If cofactor is prime, ECM will proceed to the next input in the file. You might also like to run ecm v 25e4 <inputfile1.txt to see some information about how many curves are recommended for a given target factor size; once the info is printed, ctrlc to end that run so it doesn't run one curve on all of your numbers. If you have python on your machine, or are willing to install it, ecm.py is a nice script for automating multiple threads on a single ECM effort, very useful for large jobs like T45 and up. Not so sure it's worth your time for T30 sized efforts, though. 
20220109, 11:56  #1001 
Sep 2008
Kansas
5×17×41 Posts 

Thread Tools  
Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
Passive Pascal  Xyzzy  GPU Computing  1  20170517 20:22 
Tesla P100 — 5.4 DP TeraFLOPS — Pascal  Mark Rose  GPU Computing  52  20160702 12:11 
Nvidia Pascal, a third of DP  firejuggler  GPU Computing  12  20160223 06:55 
Calculating perfect numbers in Pascal  Elhueno  Homework Help  5  20080612 16:37 
Factorization attempt to a c163  a new Odd Perfect Number roadblock  jchein1  Factoring  30  20050530 14:43 