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Subject: Re: Let's talk about fraud.

Author: Rolf Tueschen

Date: 18:44:05 05/02/04

Go up one level in this thread


On May 02, 2004 at 21:03:06, Robert Hyatt wrote:

>On May 02, 2004 at 19:36:13, Gian-Carlo Pascutto wrote:
>
>>On May 02, 2004 at 18:49:38, Robert Hyatt wrote:
>>
>>>On May 02, 2004 at 18:23:44, Gian-Carlo Pascutto wrote:
>>>
>>>>On May 02, 2004 at 13:12:04, Robert Hyatt wrote:
>>>>
>>>>>He sent me an email trying to justify his poor performance.  He first claimed
>>>>>that it was an artifact of null-move.  Testing disproved that.
>>>>
>>>>What testing?
>>>>
>>>>--
>>>>GCP
>>>
>>>
>>>The testing you and I both did.  It showed a minimal speedup difference if you
>>>recall.  2.8 vs 3.1...  not _that_ significant...
>>
>>For 4 processors, it looks small (I don't happen to agree an 11% speed
>>decrease is 'not significant' - I would be very happy which such a speedup).
>>But it's not that easy to get that 0.3 back. The real problem is that
>>scalability is reduced, and there are consequences at 8 or 16 cpus.
>
>I don't see any at 8.  I don't personally have access to a 16-way box yet so I
>can't say anything there.  But there is nothing that really makes null-move hurt
>parallel search...
>
>
>>
>>As far as I'm concernced, the testing showed that Vincent was right and
>>that recursive nullmove *does* change things. You were firmly claiming
>>that it didn't matter a thing, before. So your recollection of whose
>>claims were disproven is certainly a bit selective, to say the least.
>
>
>No.  You have always had a selective memory when it comes to Vincent.  His claim
>was that null-move made a _huge_ difference...  going from 2.8 to 3.1 is _not_ a
>huge difference on 4 cpus.  It is a difference.  But it is within the noise
>range for non-deterministic behavior anyway...
>
>That was a red herring from the get-go...

I fear he cant know the meaning of the term "artefact". Perhaps that caused
confusion.


>
>
>
>
>>
>>--
>>GCP



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