curios question...

pacionet · 2005-10-28, 09:29

I 've seen that Mersenne primes are checked at least 3 times:

1 by the discoverer
1 by Tony Reix
1 by Guillermo Ballester

No other checks are done ?
How long does the fastest supercomputer (136800 GigaFlops) take to verify the largest Mersenne known (with prime95) ?

Thanks

Bundu · 2005-11-01, 21:55

I don't know the answer to your question. But I noticed that the blue supercomper you're referring to has DOUBLED in capacity!!! Check it out

http://www.localtechwire.com/article.cfm?u=12630

pacionet · 2005-11-02, 00:45

[QUOTE=Bundu]I don't know the answer to your question. But I noticed that the blue supercomper you're referring to has DOUBLED in capacity!!! Check it out

Yes , now it should be 287,334 GFlops/s

(they didn't build the entire computer before ... )
If we know how many flop a 10 million digit prime requires (totally) we can compute

287334 / 10-million-prime-flops = how many seconds Blue Gene L requires

Why don't GIMPS or somebody borrows this supercomputer for one day and check as many exponents as possible ?

GIMPS current speed: 19686 Gflop/s
Blue Gene L speed: 287334 GFlop/s

Blue Gene L = 14.595 * GIMPS

ColdFury · 2005-11-02, 04:28

It doesn't work like that. Using Gigaflops to compare performance between totally different architectures is for the most part meaningless.

jinydu · 2005-11-02, 06:22

Also, I think it is very unlikely that Prime95 has been optimized to work well on Blue Gene.

2005-10-28, 09:29	#1
pacionet Oct 2005 Italy 3·113 Posts	curios question... I 've seen that Mersenne primes are checked at least 3 times: 1 by the discoverer 1 by Tony Reix 1 by Guillermo Ballester No other checks are done ? How long does the fastest supercomputer (136800 GigaFlops) take to verify the largest Mersenne known (with prime95) ? Thanks

2005-11-02, 00:45	#3
pacionet Oct 2005 Italy 3·113 Posts	Doubled ... [QUOTE=Bundu]I don't know the answer to your question. But I noticed that the blue supercomper you're referring to has DOUBLED in capacity!!! Check it out Yes , now it should be 287,334 GFlops/s (they didn't build the entire computer before ... ) If we know how many flop a 10 million digit prime requires (totally) we can compute 287334 / 10-million-prime-flops = how many seconds Blue Gene L requires Why don't GIMPS or somebody borrows this supercomputer for one day and check as many exponents as possible ? GIMPS current speed: 19686 Gflop/s Blue Gene L speed: 287334 GFlop/s Blue Gene L = 14.595 * GIMPS

2005-11-01, 21:55	#2
Bundu Jul 2004 Mid Calder, Scotland 5·37 Posts	I don't know the answer to your question. But I noticed that the blue supercomper you're referring to has DOUBLED in capacity!!! Check it out http://www.localtechwire.com/article.cfm?u=12630

2005-11-02, 04:28	#4
ColdFury Aug 2002 2⁶×5 Posts	It doesn't work like that. Using Gigaflops to compare performance between totally different architectures is for the most part meaningless.

2005-11-02, 06:22	#5
jinydu Dec 2003 Hopefully Near M48 2×3×293 Posts	Also, I think it is very unlikely that Prime95 has been optimized to work well on Blue Gene.