> This idea is rather obvious, and no, I don't remember seeing it either.
This had been discussed earlier. Brian and I talked about it for a little
while, he came up with the original idea.
> I think the idea has definite merit. If an error does occur, it's equally
> likely to happen at any step along the way, statistically. Errors are every
> bit as likely to happen on the very first iteration as they are during the
> 50% mark, or the 32.6% mark, or on the very last iteration.
True, but if the system is malfunctioning then the errors should start
early.
> Especially as the exponents get larger and larger, I see a *definite*
> possibility to reduce double check times by having first time LL tests
> report residues at certain "percentages" along the way.
Yeah. The error rate should be proportional to the runtime which is increases
with the square of the exponent (ouch!).
> Just for example, every 10% along the way, it'll send it's current residue
> to the Primenet server.
I'm guessing that you mean a certain amount of the residue. Sending in
10 2meg files for *each* exponent in the 20,000,000 range would get very
unwieldy, and inconvenient for people and primenet.
Of course, this would only help if we were running more one test for the
same exponent at the same time (otherwise, this would just be a pointless
way to do a triple check). They would either have to be coordinated
(running at the same time, logistical knightmare), or (as Brian suggested)
have a "pool" of exponents running on one computer. That is to say when
one computer finishes to X%, it reports its 64-bit residue to primenet, and
waits for the second computer working on the same LL test to do the same.
Until the other (slower) computer reports in, the (faster) computer works on
another exponent.
This would speed up the entire project, but it would slow down the individual
exponent, which would make people mad :(.
> I forget the numbers being tossed around,
> but you'd only save 50% of (the error rate) of the
> checking time.
As I pointed out above, the error rate should increase with the square of the
exponent (plus change). This means that if 1% have errors at 7mil, 22% will
have errors at 30mil.
-Lucas Wiman
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