Computer Chess Club Archives




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

Author: leonid

Date: 06:31:03 01/26/00

Go up one level in this thread

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
>>>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.  :)
>>>>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?


>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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