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Subject: Re: For Dr. Robert Hyatt

Author: Robert Hyatt

Date: 18:14:08 12/31/03

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On December 31, 2003 at 14:17:48, Russell Reagan wrote:

>On December 31, 2003 at 08:24:55, Ed Trice wrote:
>
>>At that point in time I had a crude bitboard move generator in place for Gothic
>>Chess. It was not hooked up to an alpha-beta procedure, nor any type of
>>evaluation function. Even with these caveats in place, the individual persisted
>>in asking me performance-related questions.
>>
>>The only way I could test the engine was to call the move generator in a for
>>loop and time it. Again, this would be like detaching Crafty from the rest of
>>its engine, then seeing how quickly it could generate moves.
>>
>>My numbers were of the order of magnitude you mentioned, but I do not have the
>>exact figures.
>
>The problem here is that you can test that exact same thing in Crafty (and other
>programs), and they don't come anywhere close to your numbers. Crafty generates
>22 million moves per second on my Athlon 2GHz, while you generate 140 million
>per second on a PIII 2GHz (which I've never heard of, but whatever). Even Yace
>(an array based program, AFAIK) gets *only* 46 million moves per second on my
>machine. Your numbers even blow away Crafty's numbers from a quad Opteron, which
>generates 38 million moves per second.
>
>Since you are using 80-bit bitboards, your numbers should be slower than Crafty
>using 64-bit bitboards, and certainly slower than an array based move generator.

Note that isn't necessarily so.  With an 80 bit board, you can actually
generate _more_ moves per piece, which will make things go a bit faster.
IE sliding pieces in particular can slide farther...

>
>Something doesn't add up. That seems to be very common with things you write.
>You seem to be mainly interested in self promotion and appearing to know what
>you're talking about regardless of what is fact and what is fiction.
>
>Take your webpage here for example:
>http://www.gothicchess.org/gothic_vortex.html
>
>You write:
>
>"On the minus side, an Array Move Generator is many times slower than a Bitboard
>Move Generator. A recent experiment showed that the Bitboard Move Generator in
>the Gothic Vortex program is about 30 times as fast as the Array Move Generator
>found in the Zillions-Of-Games engine."
>
>I'm pretty sure every experienced computer chess programmer would disagree that
>array based move generators are many times slower than a bitboard move
>generator, especially on 32-bit hardware.
>
>You frequently compare your program with Zillions of Games, and then declare
>your program to be a monster because it beats it 3-0, or runs 30 times faster,
>or whatever. This is nothing but a straw man. Zillions of Games is not optimized
>for any game. It is a general game playing program that will play any game that
>you "teach" it to play. We could all make wild claims if we found the slowest
>program on earth and made all of our claims based upon a comparison between the
>two.
>
>So like I said, something doesn't add up. Either you're making up numbers, or
>you have some secret that is allowing you to blow away every other PC program on
>earth, or there is something else you're leaving out.



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