What is the next B1?

ET_ · 2017-03-06, 09:35

I am focusing on ECM on Fermat numbers with mprime.

My question is: what is the next B1 range for F12, after 800,000,000?
I have heard people doing B1 = 2,900,000,000, is it correct?

swellman · 2017-03-06, 12:33

Quote:

Originally Posted by ET_

I am focusing on ECM on Fermat numbers with mprime.

My question is: what is the next B1 range for F12, after 800,000,000?
I have heard people doing B1 = 2,900,000,000, is it correct?

https://members.loria.fr/PZimmermann...cm/params.html

ET_ · 2017-03-06, 14:42

Quote:

Originally Posted by swellman

https://members.loria.fr/PZimmermann...cm/params.html

Thank you swellman. I was asking basicly for 2 reasons:

1 - I am using mprime, not GMP-ECM: mprime has different B2 parametrization.
2 - The page at https://www.mersenne.org/report_ecm/ based on mprime work over Fermat ecm shows B1 = 800,000,000 instead of 850,000,000.

Luigi

swellman · 2017-03-06, 15:56

Sorry I missed the fact you're using mprime. Don't have optimal parameters for it, though I suspect they are close to gmp-ecm in magnitude. Good luck!

henryzz · 2017-03-06, 16:21

If you are talking about optimal you would change the bounds after every curve.

Here is some reading
http://www.mersenneforum.org/showthread.php?t=21420

2017-03-06, 09:35	#1
ET_ Banned "Luigi" Aug 2002 Team Italia 2²·7·173 Posts	What is the next B1? I am focusing on ECM on Fermat numbers with mprime. My question is: what is the next B1 range for F12, after 800,000,000? I have heard people doing B1 = 2,900,000,000, is it correct?

2017-03-06, 15:56	#4
swellman Jun 2012 11²×29 Posts	Sorry I missed the fact you're using mprime. Don't have optimal parameters for it, though I suspect they are close to gmp-ecm in magnitude. Good luck!

2017-03-06, 16:21	#5
henryzz Just call me Henry "David" Sep 2007 Liverpool (GMT/BST) 5985₁₀ Posts	If you are talking about optimal you would change the bounds after every curve. Here is some reading http://www.mersenneforum.org/showthread.php?t=21420