The ECM choice lets you factor
Mersenne numbers using the Elliptic Curve Method of factoring. Select a few exponents and bounds to factor
from the http://www.mersenne.org/ecm.htm
web pages.
Note: You do
not reserve exponents to work on, several people can do ECM factoring on the
same exponent. The program uses a
random number generator to select elliptic curves to test. You must email results to me at woltman@alum.mit.edu - PrimeNet
does not support ECM factoring.
WARNING: ECM does not adhere to
the memory limits specified in the Options / CPU dialog box. ECM requires a minimum of 192 times the FFT
size. Thus, ECM factoring of F20 which
uses a 64K FFT will use a minimum of 192 * 64K or 12MB of memory. You can also edit the
worktodo.ini
file directly. For example:
ECM=751,3000000,0,100,0,0,0,0
The first value is the exponent. The second value is bound #1. The third value is bound #2 - leave it as
zero. The fourth value is the number of
curves to test. The fifth value is no
longer used. The sixth value is the
specific curve to test - it is only used in debugging. The seventh value is 0 for 2^N-1 factoring,
1 for 2^N+1 factoring. The eighth value
is no longer used.