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Subject: Re: HYDRA vs RYBKA !!

Author: Chrilly Donninger

Date: 11:38:48 12/12/05

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On December 12, 2005 at 13:48:30, Zappa wrote:

>On December 12, 2005 at 13:15:05, Joshua Shriver wrote:
>>Imagine Rybka on Hydra hardware and interface card to the FPGA boards :)
>>On December 12, 2005 at 12:56:41, Ziad Haddad wrote:
>>>Is this match possible in the future? Could hydra hold on? Did a multiple CPU
>>>version of Rybka will be available? Hydra must fear this.
>I can't stand comments like this.
>In order to port an engine to hardware, you basically have to rewrite it from
>scratch (admittedly using the same ideas, but still).  It'd only be 2 years of
>work or so  . . .

Well, the main problem is, that you can not even use the same ideas. Its a
different world and one has to find own solutions. Forgetting about Nimzo was
the hardest part in the Brutus/Hydra project. This is in both directions. Some
things which one avoids in software, because they are very inefficient, are in
hardware cheap. One has to overcome the old reluctance to implement these. E.g.
In Nimzo I had only a fast approximation for mobility terms. Accurate mobility
is almost free on the hardware. Some constructs are in contrast on the FPGA
almost impossible. E.g. the size of RAM-Tables is fixed to 4 (old Virtex-I) and
now 18-KBits (Bits not Bytes). One has to split up everything that it fits into
these small tables. And one has also to restrict the possible values. A typical
Hydra-Tables as 12 Bits Input and 4 Bits output or just 16 different values.
One has also to avoid any sequential thinking. E.g. I calculate first the pawn
structure and the rest of the eval depends on this. In Hardware this runs all
parallel. If one makes it sequential, one has already lost. The hardware only
excells, if one can use the full parallelism. The clock is on the Intel chips
60x times faster.


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