On Sun, Sep 10, 2000 3:25 PM, Colin Percival <[EMAIL PROTECTED]> wrote:
> Or we might just be unlucky. There are inputs for which the
>multiplication used in prime95 will not give the correct answer --
>fortunately they are very rare and it is very unlikely that any would ever
>be encountered. (It isn't worth using safe multiplications because any
>problems will show up in the double check anyway.)
This reminds me of something I've been meaning to ask about double
checking.
I looked at a bit of the database of double-checked exponents:
ftp://mersenne.org/gimps/lucas_v.zip
I noticed some exponents where the first-time and double-check results were
submitted by the same person, using the same software, on the same machine.
If there is a reproducible hardware problem, or one of these "bad"
multiplications, then this double-check would not catch an error.
Actually,
I kind of doubt that the LL test was done twice. More likely one result
was accidentally _submitted_ twice, and the friendly primenet server
happily
accepted both. (We know that the primenet server accepts results from
people who do NOT have the exponents assigned to them.)
Will these seemingly bogus double-checks be weeded out when the next
synchronization is done?
---------------------------
Robert Deininger
[EMAIL PROTECTED]
_________________________________________________________________________
Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm
Mersenne Prime FAQ -- http://www.exu.ilstu.edu/mersenne/faq-mers.txt
