Hi,
At 11:00 AM 10/12/99 -0400, Darxus wrote:
>704.5 days to go on this 10m digit prime my computer at home is working
>on. P2 233. 1.93 years.
I admire your patience!
> I think it said 1 in 250,000 chance if finding
>a prime. So.. on average, it would probably take that one computer, by
>itself, 241,250 years to find a 10m digit prime. Right ?
Define "probably". 241,250 years gives you a 50% chance. Actually it will
take longer since the exponents get bigger and bigger.
>it'd be good to break up
>primes into like, 1 month chunks, & distribute them.
A good idea but the Lucas-Lehmer primality test is a "serial" algorithm.
That is, I can't have 33 machines each do a million iterations and get the
answer in a month. The second million iterations can't start until the
first million complete.
It would be nice if someone invented a primality test that could be done
in parallel.
>I also think it would have been better to award $5k per new prime, of any
>length. But that's just my opinion.
The prize fund was set up by the EFF and the anonymous donor. I agree with
you and have tried to encourage an orderly progression by awarding $5,000
to all smaller Mersenne primes (but only if we also find the 10 million
digit prime).
>And how is the probability of finding a prime calculated ?
It is roughly how-far-factored-in-bits * 2 / exponent
>I wanna do a comparison of the prize money to probability ratio between
>distributed.net's rc5-64 project ($2k prize), & GIMPS 10m digit prime
>($55k prize). But it'll take me a chunk of time. Any estimates ?
There is now a prize for factoring Fermat numbers too.
However, the best investment is probably to turn off your computer
and pocket the $30 you save in electricity! Of course, that's no fun.
So pick whichever project gives you the biggest thrill.
Regards,
George
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