Computer Chess Club Archives




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

Author: leonid

Date: 14:21:36 01/26/00

Go up one level in this thread

On January 26, 2000 at 09:54:48, Robert Hyatt wrote:

>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
>>>>>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?
>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.

800k (nodes per second) on 1600Mhz sound to me as extremely speedy. Maybe Xeon
is also the 64 bits computer. This could explain this speed excess with what I
could expect. I compare your speed with one PC game written on Assembler. Your
speed just shine.


>>>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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