24737*2^991+1 smallest unfactored k/n pair

[SlicerAce]

Haha, I suspected something like that - I had always wondered if the ECM factoring program being implemented in Java would cause trouble (read: slowdowns).

I'm working on compiling a version of GMP-ECM 6 using MinGW and MSys, just like in the thread you posted. I'll be compiling it for the athlon-xp using the -mtune switch on GCC.

Doesn't this program run into some problems with the stack size? i.e. Large numbers like the ones dealt with in SoB cause some sort of overflow? I know that was the case when I downloaded an older, precompiled version of ecm.exe, however I'd like to know how to setup GCC to organize the memory allocation correctly

By the way, are there any instructions anywhere on how to get Prime95 and ECM6 to work together? i.e. How do I get Prime95 to do only stage 1 and ECM6 to pick up where Prime95 left off and do only stage 2?

I have Prime95 setup using:

ECM2=24737,2,991,1,43000000,4300000000,700

700 is just an arbitrary number, just so that I don't go back to P-1 factoring of other numbers. In terms of trying to get Prime95 to do only stage 1, is having that B1*100 limit in there (the worktodo.ini file, above) a smart thing? In fact, shouldn't I set this to 0 or something or else it will start doing stage2? I'll have to wait and see.

I also want to make sure of this: Are these curves chosen randomly i.e. are we both doing different pieces of work? I'll assume yes.

I hope this only does stage 1 ECM factoring heh.

Update:

Mystwalker posted a bunch of great information on how to get some of this going

http://rieselsieve.com/forum/viewtopic.php?p=4878#4878

Another update:

I've found that I need to set B2 in between 1 and B1 in order for Prime95 to forfeit running stage 2. However, I had B2 set to 0 and Prime95 did not write my first curve to results.txt A file, 'd0000991' was written to my prime95 directory, and it contains a bunch of gibberish. I'm not sure if I can use this or what I'm supposed to do with it!

I'm now running the below in my worktodo.ini file:

ECM2=24737,2,991,1,43000000,10,700

Also, I'm looking over some of the options in gmp-ecm, and could someone explain to me what the Brent-Suyama extension is? Could someone also explain to me what a Dickson polynomial is? I'm guessing it's some sort of special polynomial form, as there's also the option to use x^n as a polynomial for this Brent-Suyama extension

Can we use any of these options to our advantage? How does one choose correct n values for the x^n polynomial/how does one choose the correct Dickson polynomial number?

Another update:

Prime95 is now writing Stage 1 residues correctly to results.txt.
I now have my laptop (p4 2.66ghz) running Prime95 stage 1 as well for the same number. As far as stage 2 goes, Mystwalker had posted in a thread somewhere that he used the flag -k 4 for gmp-ecm for a 1024MB system (which is what I have), so I'll be using -k 4 when I finally get around to crunching all these stage 2 curves.