On 16 Jun 99, at 0:25, Steinar H. Gunderson wrote:
> >This is why George no longer supports
> >it in the CPU check boxes. I wonder how long it will be before he drops
> >486's.
>
> Hopefully there will be a while to -- my 486s are all performing excellent
> factoring.
>
Well, you don't _have_ to update your software. And, if PrimeNet
decides to "disown" 486's, you can still use the manual pages.
>
> And if `most sense' is applied? Will a PII only get LL assignments, or
> nothing? (Currently, this isn't a big problem, though.)
Yes - so long as the _effective_ cpu speed (MHz * hrs per day/24 *
RollingAverage/1000) exceeds whatever the cutover point between LL
and double checking is. Somewhere around 170 MHz now, I think, the
program code increases this linearly from 120 to 200 over a year
since it was released.
If you run a PII-266 12 hours a day, you'll end up getting double
checking assignments (at least once the RollingAverage has
stabilised).
>
> >transaction object. This is where we set rules like, 'give all v17 clients
> >double-checking work'
>
> Hmmmm, I thought they were bugged?
>
v17 is fine for exponents < 2^22 (4194304). However, for larger
exponents, the LL testing code (which is the same as the double
checking code) goes wrong straight away. Importing a save file for
_any_ exponent written by any version _except_ v17 and finishing it
with v17 is also OK.
So long as double-checking assignments have exponents less than 2^22,
the server-imposed rule is OK. But we're starting to close in on 2^22
- Scott, this rule may need to be looked at in a month or two!
Having said all that, v18 seems solid, I see no reason why anyone
still running v17 (or earlier) shouldn't upgrade.
> (From what I've read on this list, there are two different series of LL
> numbers. Perhaps I'm just way off here.)
Well, actually, there are _lots_ of them ... this is because, for
many integers y in [0 , 2^p-1] there is more than one integer x such
that x^2-2 (mod 2^p-1) = y.
The starting value 4 is convenient because it works with _all_
exponents. So does, e.g., 10, but although both sequences starting
with 4 and 10 end with residual 0 at iteration p-2 if 2^p-1 happens
to be prime, the final residuals for the two sequences may not be
equal if 2^p-1 happens to be compound. (In fact, they're not likely
to be equal). Using a fixed starting value is helpful for cross-
checking results, and helps keep the code relatively simple.
Regards
Brian Beesley
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