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Subject: Re: Does Hydra try to avoid a second Leiden?

Author: Robert Hyatt

Date: 15:04:25 05/19/04

Go up one level in this thread


On May 19, 2004 at 16:39:29, Robert C Gates wrote:

>On May 19, 2004 at 10:51:41, Vincent Diepeveen wrote:
>
>>On May 19, 2004 at 10:18:01, Ingo Althofer wrote:
>>
>>>In the Leiden tournament (in April 2004) Hydra was terribly bashed by Shredder.
>>>Perhaps after that they only play in events without Shredder.  ;)
>>>
>>>Ingo Althofer.
>>
>>I feel we must not be too hard judging the hydra team. It's the sheikh who
>>doesn't want to join in Israel. I'm sure the entire team wants to.
>>
>>However any claim that Hydra is the strongest chess program on earth must be
>>forgotten. It was very lucky in Leiden in many games. I'm sure the quick level
>>of 90 0 and majority of participants not using big hardware has lead to Hydra
>>scoring more points than it based upon what it showed earned IMHO.
>>
>>Basically the ultra agressive speculative evaluation which Hydra uses to play
>>means it will never win a world title. Ultra agressive behaviour has 2
>>advantages :
>>  a) you kill every bad tested program with big bugs left in eval (especially
>>king safety) thanks to agressive attack and big search depth.
>>  b) it has a nice playing style. attack attack without looking back...
>>
>>It has 1 major disadvantage:
>>  a) it is incorrect and will simply lose in future
>>
>>Note that there is a subtle but important difference between agressive play and
>>speculative agressive play.
>>
>>So time is running out slowly for Hydra now. 1 chip is not so slow now compared
>>to software, but next year it will be when the dual opterons at 1 chip start to
>>arrive.
>>
>>The software guys all will profit from hashtables a lot at opteron and each
>>generation getting faster we profit a lot.
>>
>>Hardware however doesn't profit from all that. Last 6 plies no hashtables for
>>Hydra...
>>
>>Hydra's parallel search doesn't scale to more processors easily when compared to
>>software using a hashtable. Moving from 8 to 16 processors i didn't see it
>>search deeper actually (i forgot to ask during ict4 how many processors used,
>>frankly i didn't care at that moment).
>>
>>So in 2010 they probably will be still 16 processor clocked at 33Mhz.
>>
>>Perhaps one time an update to 66Mhz and PCI-X myrinet cards (3 us one way ping
>>pong latency versus the current ones it has are like 8 us).
>>
>>So in 2004 world champs the hardware advantage from hydra would be not there,
>>but in 2005 for sure also gone against many non-world champs participants.
>>
>>What is left is a strong program definitely in world top and of course eyes
>>closed crushes software like crafty (even when using just 1 hardware processor,
>
> What do you mean Crushes programs Like Crafty? Crafty is one of the Best
>around.
>
>

Vincent never passes up an opportunity to take a swipe at any program he can't
beat through programming effort of his own...


>
>
>
>
>>because eval just matters).
>>
>>However it is outdated right now IMHO.
>>
>>It's advantage IMHO was using 8-16 processors, not for being in hardware.
>>
>>And knowing the parallel skills of the university paderborn (feldman & co)
>>adding more processors we can only expect a slowdown.
>>
>>When running at 460 processors with diep i did several experiments turning off
>>hashtable last few plies and had very discouraging results there.
>>
>>Note that Feldmann correctly had already concluded this years ago (that one
>>*needs* to do hashtable lookups everywhere; for me it is amazing that Feldmann
>>could draw so many correct conclusions with such bad software implementations).



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