At 07:54 PM 3/7/2000 -0000, Brian J. Beesley wrote:
(many detail comments deleted, wherein Brian sets the record straight)
>I've just put the file back up. Sorry, it got removed accidentally
>when I upgraded the server hardware about three months ago.
Thanks, that's useful.
>[ Ernst Mayer comments ]
>> >So, it doesn't look like testing exponents above ~40M is going to
>> >be practicable any time soon, where I mean doable in a year or less. But
>> >since the vast majority of GIMPS first-time LL tests won't even be
>> >approaching 20M for some years yet, having one or two double-checked
>> >exponents in each subrange below 39M would seem sufficient for the next
>> >couple of years.
>
>I agree. Of course, anyone who thinks it's _fun_ to tie up a system
>for several years running a LL test on a larger exponent is quite
>welcome to do so, so far as I'm concerned!
Well, I'm one of those folks who regards it as much more fun to have
cpus fully occupied than idle, and believes the scouts should be well
ahead of the army.
Ken said, in regard to partially completed runs:
>> I'd like to see them get cpu credit, but I am not in a position to
>> guarantee it.
>
>George seems to add the CPU credit from QA tests to his records. So
>far as PrimeNet is concerned, we (deliberately) don't use PrimeNet to
>communicate results; in any case PrimeNet doesn't recognize that we
>own the QA assignments (some of them are actually triple-checks & the
>rest are outside currently active ranges), which is why they "don't
>count". This doesn't bother me, but it should be easy enough to fix.
So far as I know, George treats full LL tests from the QA group like any
other manually reported results; credit is given.
>> Most of the effort would fall on someone else, and I'd rather see George
>> and Scott doing other things than the bookkeeping of apportioning credit
>> by iteration count and exponent size and checks of usable save files. To
>> keep the minimum contribution sizable, I ask the volunteers to commit to
>> at least a half-PII-400-year; large contributions are more likely to
>> justify crediting the work or a partial large exponent.
>>
>I'd strongly reccomend anyone running PrimeNet 10 million digit
>assignments to place the following line in their prime.ini file:
>
>InterimFiles=1000000
>
>This will cause the interim residual to be written to results.txt
>every 1000000 iterations. At the same time, an extra save file will
>be written. The idea is that, when double-checking is scheduled on
>this exponent, any error can be found without neccessarily having to
>complete the whole run to find it, thus saving time. Also, in the
>event that a prime is found, with a set of interim save files we will
>be able to verify the result much more quickly by running 1000000
>iterations on thirty odd systems in parallel.
Personally, I'd prefer 2000000 for the bigger exponents, but that's
personal taste.
Ideally, in a future version of prime95 and primenet, the interim residues
will be
handled over IPS and include some tiebreaker strategy. The observed trend is
for LL tests to be less reliable with increasing exponent, due to
increasing runtime,
so an automated way of detecting and handling mismatches in interim residue
becomes increasingly important as the average available exponent increases.
>If you're worried about disk space, delete the extra save files; the
>interim residual has considerable value in itself.
>
>Also could anyone dropping out of a large exponent run (including
>PrimeNet 10 million digit range assignments) please send in a copy of
>their last savefile, so that work completed isn't lost. My server has
>lots of space available for this task.
I've made the standing offer before, of anyone with large exponents & wanting
to quit, that the QA group will take them on for completion.
Brian's ftp server is an ideal drop point.
Ken
>
>Regards
>Brian Beesley
>
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