mersenneforum.org - View Single Post - (may be) stupid idea for speed of mersenne-LLT

Random_zh · 2006-11-23, 19:35

Hi all. I have an idea how to may be speed or slow down LL test. I just dont know how FFT multiplication behaves with even larger numbers.

you could test 2 or more numbers at same time:

example for the iterations with 3 exponents p,q,r:
S(0) = 4
S(n+1) = S(n)^2-2 mod (2^p-1 * 2^q-1 * 2^p-1)
test p,q,r like always:
S(p-2) mod (2^p-1)
S(q-2) mod (2^q-1)
S(r-2) mod (2^r-1)

hmm i guess it will cost more time with larger numbers, but since i'm not sure... :)

2006-11-23, 19:35	#1
Random_zh Nov 2006 2 Posts	(may be) stupid idea for speed of mersenne-LLT Hi all. I have an idea how to may be speed or slow down LL test. I just dont know how FFT multiplication behaves with even larger numbers. you could test 2 or more numbers at same time: example for the iterations with 3 exponents p,q,r: S(0) = 4 S(n+1) = S(n)^2-2 mod (2^p-1 * 2^q-1 * 2^p-1) test p,q,r like always: S(p-2) mod (2^p-1) S(q-2) mod (2^q-1) S(r-2) mod (2^r-1) hmm i guess it will cost more time with larger numbers, but since i'm not sure... :)