mersenneforum.org Introduction: ECM work done on Cunningham Project composites
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2005-01-11, 22:08   #1
garo

Aug 2002
Termonfeckin, IE

22·691 Posts
Introduction: ECM work done on Cunningham Project composites

In this subforum we are attempting to summarize the amount of ECM work
known to have been done on the Cunningham Table composites.

Several changes have been introduced from version 2.0. Hence the description below in quotes is not accurate anymore. I am leaving this in only for record-keeping purposes. please read the new introduction at:http://www.mersenneforum.org/showthread.php?p=58344
Quote:
garo and xilman (aka Paul Leyland)

Last fiddled with by garo on 2005-08-01 at 15:17 Reason: Changed to reflect the new tables with new B1 boundaries.

 2005-01-18, 18:23 #2 garo     Aug 2002 Termonfeckin, IE 22×691 Posts The following is a summary of number of curves that need to be run on a composite before a given level is declared as done. I have taken this snippet from Paul Zimmerman's ECMNet page at http://webloria.loria.fr/~zimmerma/records/ecmnet.html Note that if you used GMP-ECM5.0 the curves must be translated to their ECM6.0 equivalent. Though you really should not be using GMP-ECM5.0 as v6 is much faster!! Code: digits optimal B1 expected curves expected curves (B2=100*B1) (default parameters for ecm-6.0) 20 11,000 84 77 25 50,000 262 206 30 250,000 648 401 35 1,000,000 1,588 948 40 3,000,000 4,716 2,440 45 11,000,000 9,770 4,590 50 43,000,000 18,143 7,771 55 110,000,000 45,841 17,899 60 260,000,000 114,973 43,670 65 850,000,000 193,436 69,351 Finally, numbers marked as resv have been reserved for GNFS/SNFS and thus no further ECM is required on these numbers. Last fiddled with by garo on 2005-08-01 at 15:40
2005-01-20, 10:06   #3
garo

Aug 2002
Termonfeckin, IE

22·691 Posts

I think thiscomment from rogue deserves being repeated here. So starting with 45digits is preferable for composites above 195 bits and at 50 digits is preferable for composites between 146-195 bits.

Quote:
 Originally Posted by rogue 1) that composites < 145 digits are ready for sieving, I assume most of these are reserved 2) that composites > 145 and < 196 should use B1=43e6 (50 bits) at a minimum and have about 1/3 of required number of curves done at that B1 3) that composites > 195 should use B1=11e6 (45 digits) at a minimum

Last fiddled with by garo on 2005-07-28 at 16:02

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