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Subject: Re: Nodes per second........

Author: James Robertson

Date: 14:54:35 09/26/98

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On September 26, 1998 at 17:30:09, John Coffey wrote:

>On September 26, 1998 at 17:21:58, James Robertson wrote:
>>What is a reasonable number of NPS for a program to search if it has an average
>>sized evaluation procedure? I.E. what does Crafty get? Chessmaster? Comet? My
>>program started out searching a very nice number of nodes per second, but as I
>>added stuff that number decreased dramatically from about 600,000 to 160,000. By
>>the time I finish the evaluation function (which is currently like 20 lines),
>>I'm afraid it will be down to like 5,000 NPS on my P233! At what point should I
>>get worried?
>This is an interesting question, because Robert Hyatt told me the other day
>that it was the size of the tree and not the NPS that really matter.  When
>I looked at the Crafty source code, I was surprised at how much code that
>gets executed for every single node.  But the main purpose of that code is
>to cut down the size of the tree (using null moves, hash tables, move ordering,
>etc.) That tree  grows exponentially, so cutting it from say 6^N down to 3^N
>is a huge improvement regardless of the number of nodes per second.
>Fritz 5 is suppose to use about a 1,000 clock cycles per node.  Crafty gets
>80,000 nodes on a Pentium 200 mmx, so that works out to be about 2,500 clock
>cycles per node.  But Crafty is still very very strong.
>John Coffey

Yeah, my tree size has diminished a lot since I added all that move ordering
stuff. How on earth does Fritz take only 1,000 clock cycles per node??


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