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Subject: Re: DB NPS (anyone know the position used)?

Author: Robert Hyatt

Date: 06:54:48 01/26/00

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On January 26, 2000 at 09:31:03, leonid wrote:

>On January 25, 2000 at 23:50:51, Robert Hyatt wrote:
>
>>On January 25, 2000 at 21:21:53, Chris Carson wrote:
>>
>>>On January 25, 2000 at 20:56:21, Peter W. Gillgasch wrote:
>>>
>>>>On January 25, 2000 at 08:46:27, Chris Carson wrote:
>>>>
>>>>>Does anyone know what position(s) HSU used
>>>>>to get the 100M NPS (DB) or 200M NPS for
>>>>>DBII?
>>>>
>>>>Why do you think that the position matters
>>>>at all ? As long as he can keep the chips
>>>>busy the total number of cycles should be
>>>>constant. Since he was doing the last 4 plies
>>>>in hardware - and that means that he basically
>>>>did all the positions in hardware - I suspect
>>>>that the overhead onthe SP which certainly
>>>>depends on the position can be neglected...
>>>>Obvious, isnīt it ?
>>>>
>>>>-- Peter
>>>>
>>>>>Was it one position or many position's?  Was it
>>>>>middle game, endgame, or combination?
>>>>>
>>>>>I would like to have the EPD for the
>>>>>position, it would be interesting to
>>>>>benchmark against.  :)
>>>>>
>>>>>Thanks.
>>>>>
>>>>>Best Regards,
>>>>>Chris Carson
>>>
>>>OK, but that is not why I wanted the position.  HSU
>>>quoted the numbers and I would like to know what positions
>>>were used.
>>>
>>>Best Regards,
>>>Chris Carson
>>
>>
>>I don't think _anyone_ uses positions when they quote nodes per second.  IE
>>when I quote 800K for crafty on my quad xeon, that comes from watching a bunch
>>of games and noting the NPS as the games are played.  It runs from as low as
>>550K to about 1M on my xeon.  But once castled, it averages about 800K for the
>>rest of the game...
>
>
>And what are the main characteristics for "Quad Xeon" ? Quad probably stay for
>four processors, but how about the speed of each chip in Mhz?
>
>Leonid.

400mhz cpus.  figuring about 75% efficiency on 4 cpus, that is roughly like
a 1200mhz xeon.  In some cases it is like a 1600mhz machine, in others it
is less than 800 although that is reasonably rare.




>
>
>
>
>>NPS is a 'vague' number since I have positions where I can hit 450K or 1.3M
>>depending on which one I use.  Most of use use actual game numbers as a result,
>>although it doesn't mean a thing.
>>
>>In Hsu's case, he can't _really_ give an exact nps, because the hardware
>>processors don't count nodes. It would take them as long to count one as it
>>does to search one.  He seems to have an idea that they drove the chess
>>processors at 50-70% utilization.  Which would translate into roughly 500-700M
>>nodes per second, raw numbers.  He also claimed 30% search efficiency, which
>>most likely turns into the 200M number.  IE for Crafty, the raw NPS is 800K.
>>But due to extra work done, this is probably equivalent to 600K overall.
>>
>>I am not certain how he arrived at 200M, but that is a reasonable guess.  Based
>>on 480 chess processors at 2M to 2.4M nodes per second.  taking the lower number
>>(some were clocked at 20mhz, others at 24mhz) we get almost 1B nodes per second
>>max, but he couldn't keep them all busy.  .70 * 1B = 700M.  .30 * 700M = 210M,
>>which was the claimed speed...



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