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Subject: Re: New crap statement ? Perpetuum mobile

Author: Dave Gomboc

Date: 21:28:35 10/03/01

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On October 04, 2001 at 00:11:37, Uri Blass wrote:

>On October 03, 2001 at 18:53:31, Dave Gomboc wrote:
>
>>Observing that the parallel algorithm was super-linearly quicker immediately
>>gives rise to a superior sequential algorithm: alternate checking from the front
>>of the array and the back of the array for the zero.  It would quickly be
>>observed that the parallel algorithm does not have super-linear speedup over
>>this superior sequential algorithm.  In addition, the sequential algorithm may
>>be further optimized by ignoring the front of the array altogether, which would
>>reduce the parallel speedup further.
>>
>>To ignore the superior sequential algorithm and instead publish results
>>comparing only the original, poor sequential algorithm with the parallel
>>algorithm is not merely disingenuous but simply bad science.
>>
>>Dave
>
>The question here is a practical question.
>
>It is possible that the original sequential algorithm that chess programs use is
>a poor algorithm and this is the point of Bruce.
>
>Uri

And that point was already superseded weeks ago.  Both Bob and I have clearly
stated earlier that comparing a parallel algorithm against a _bad_ sequential
algorithm is useless.  You must compare the parallel algorithm to the _best_
available sequential algorithm.  To do anything but this is absurd, because if
you don't insiste on the best available sequential algorithm then you can report
an arbitrarily large speedup.

Once you do insist on the _best_ available sequential algorithm, overall
super-linear speedup is not possible, for the class of computations executable
by Turing machines.  ( = the claim about consistent super-linear speedup not
being possible is not made for quantum computation. )

Dave



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