Author: Uri Blass
Date: 02:52:58 04/18/02
Go up one level in this thread
On April 18, 2002 at 05:20:30, Vine Smith wrote: >On April 18, 2002 at 04:16:48, Uri Blass wrote: > >>On April 18, 2002 at 02:22:22, Slater Wold wrote: >> >>>On April 17, 2002 at 22:14:55, Vine Smith wrote: >>> >>>>Good Lord, your machine is fast, fast, fast! What is it -- I think I saw one of >>>>your posts about this but can't quite remember, something like 2x1.7 GHz >Athlon? >>> >>>Dual AMD 1.73Ghz (Athlon XP+2100) - Asus A7M266-D Mobo - 1024MB RAM - 4x36.4GB >>>SCSI - GeForce 4 >>> >>>>It seems roughly 6x as quick as PIII-850 with Junior 7 (assuming Deep Junior 7 >>>>is much the same program), whereas I would have guessed only 4x. >>> >>>Deep Junior 7 is the same program. >>> >>>>The Shredder >>>>analysis was strange -- I guess this is the only program that improves on >slower >>>>hardware! Supporting this, there was a post by Nemeth that Shredder did not play >>>>the awful moves that led to its dismal defeat by Smirin on his slower system. >>> >>>Well, I think there's more to it. If you look at position A with 2 computers, >>>the evals will usually not be a *whole* lot different (granted you're using the >>>SAME exact program). I've actually tested my machine's eval using Deep Fritz vs >>>Deep Fritz on a P200. And the PVs are almost always exactly the same. However >>>there is a LOT of randomness in a SMP search. Branching is almost completly >>>random. >>> >>>>And then there's Crafty; every time I see it fail at a tactical problem, I gain >>>>greater respect for its positional abilities, since this MUST be the way it >>>>stays at the top (versus other non-professional programs, that is). >>> >>>Crafty is a terrific program. And I believe it has just as much positional >>>understanding as any "commercial" program, perhaps even more than some. >>>However, it does sometimes lack in tactics. >>> >>>>Rightly or >>>>wrongly, DB rejected Deep Fritz's eventual choice of 36...b5 after reaching >>>>depth 11(6) -- this had been DB's move at depth 10(6) [whatever that means; 16 >>>>full-width? 10 full, 6 selective? 10 with a selective component plus 6 >>>>full-width?]. >>> >>>Yes, I looked at the log. It looked at Rd7, b5, and eventually went with Kf8 >>>after only looking at it for a short period of time. >>> >>>All of Deep Blue's searchs were full width. What I have come to understand is >>>that 10(6) represents the (6) ply done in software and the 10 shows the ply in >>>HW. The first 6 ply were always done in software, and the remainder was always >>>done in HW. >> >>Not exactly and it was explained here that 10(6) means only 10 ply brute force. >>6 plies in the hardware was based on selective search. >> >>Uri > >Was that a consensus opinion agreed to by all the parties who discussed this >matter? I remember that Hyatt asserted the two depth numbers were additive to >full-width, referring to a statement made by Hsu in a private e-mail. Then >Diepeveen disputed this with some calculations intended to prove that even a >machine as fast as DB could not have searched this deep full-width. The only >thing I remember any agreement about was that the second depth number >represented a search by the hardware nodes. Why the DB team never publicly >explained what the log files they released actually meant is a mystery, as is >the reason for keeping the code under wraps, since it seems that it will never >be used again. The information vacuum keeps many aspects of various debates >about DB alive, and there seems to be no rationale for this frustrating >situation. > >Regards, >Vine Smith I remember that somebody posted an old post from rgcc that proved that the programmers of deeper blue did not see the last 6 plies as brute force search. Uri
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