Curves needed

[henryzz]

While using the information on http://www.loria.fr/~zimmerma/records/ecm/params.html with gmp-ecm 6.1.3 i noticed that v6.1.3 wanted less curves run at most levels
why then are we still using the v6.0 amount of curves

Digits v6.0 v6.1.3 Diff
20 77 74 3
25 206 214 -8
30 401 430 -29
35 948 904 44
40 2,440 2,350 90
45 4,590 4,480 110
50 7,771 7,553 219
55 17,899 17,769 130
60 43,670 42,017 1,653
65 69,351 69,408 -57


also how are these numbers calculated

[xilman]

Originally Posted by henryzz

why then are we still using the v6.0 amount of curves

Because small changes in the number of curves makes essentially no difference to the amount of cpu time required to find factors.

Originally Posted by henryzz

also how are these numbers calculated

Left as an exercise in the use of Google.


Paul

[henryzz]

surely 1600 curves at 60 digit level is worth missing

[xilman]

Originally Posted by henryzz

surely 1600 curves at 60 digit level is worth missing

Read the numbers again.

Approximately 43K curves are recommended at this level. 1600/43K is under 4%. That in itself is barely worth worrying about. When you take into account (whiich you clearly haven't) that the extra work gives you a larger chance of finding a factor if one is to be found, then it really isn't worth making a fuss over it.


Paul