Stage 1 with mprime/prime95, stage 2 with GMP-ECM

[D. B. Staple]

There seems to be a lot of encouragement from people here to run stage one ECM with mprime/prime95, and stage two with GMP-ECM. From what I have read, a lot of work has gone into merging these two great programs, but this has all been 'beta', and due to issues / heartbreak etc. it will likely stay that way for some time.

In the meantime, the question is how exactly to go about running stage one and stage two separately. In this thread:
http://www.mersenneforum.org/showthr...mp-ecm+prime95
it is implied that copying a line from the mprime results.txt to some gmp-ecm input is sufficient. I find this strange, since the only line in my resu0000.txt file is (minus the date):
"2^1048576+1 completed 1 ECM curves, B1=1000000, B2=100000000"

To make this post more readable, I'll summarize the relevant questions here:

(1) what steps are necessary to instruct mprime/prime95 to perform only stage one, and save the results (to a gmp-ecm readable file).

(2) will doing a:
ecm -resume file B2
be sufficient to cause GMP-ECM to perform stage-2 (only) to the limit B2?

[S485122]

In Prime95's undoc.txt there is the following :

"Alexander Kruppa wrote some code that allows the output of ECM stage 1 to
be passed to Paul Zimmermann's more efficient GMP-ECM stage 2. This program(*)
is usually faster in stage 1. You can activate this feature by entering
GmpEcmHook=1
in prime.ini. Then select ECM bound #2 between 1 and bound #1. Results.txt
will contain data that can be fed to GMP-ECM for stage 2."
(*) Meaning Prime95 of course.

Jacob

[D. B. Staple]

I should have realized I was missing something simple; I only checked readme.txt and the gmp-ecm documentation, and thought that this was everything.

Thanks!