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Subject: Re: TERAS sgi 3800 origin at 1024 cpu

Author: Tony Werten

Date: 23:34:22 04/11/03

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On April 11, 2003 at 14:26:57, Vincent Diepeveen wrote:

>On April 11, 2003 at 14:06:23, Keith Evans wrote:
>
>>On April 11, 2003 at 07:56:02, Vincent Diepeveen wrote:
>>
>>>On April 10, 2003 at 17:14:21, Keith Evans wrote:
>>>
>>>>On April 10, 2003 at 15:26:24, Johan Hutting wrote:
>>>>
>>>>>On April 10, 2003 at 13:56:29, Keith Evans wrote:
>>>>>
>>>>>> Is the 500
>>>>>>processor box running Windows? Linux?
>>>>>
>>>>>Operating system: Irix
>>>>>(http://www.sara.nl/userinfo/teras/usage/progavail/irix/index.html)
>>>>>
>>>>>other stats: http://www.sara.nl/userinfo/teras/description/index.html
>>>>
>>>>Vincent are you able to run the same code on an SMP PC and on a 500 CPU CC-NUMA
>>>>machine?
>>>
>>>yes 100% the same code compiles. i do not modify a byte in fact.
>>>
>>>the makefile in irix has litterary:
>>>
>>>-DIRIX
>>>
>>>and the windows file doesn't have that one.
>>>
>>>in my diep.h:
>>>
>>>#if IRIX
>>>  #define MAXPROCESSES 512
>>>#else
>>>  #define MAXPROCESSES 16  // right now, used to be 8 ;)
>>>
>>>>Curious,
>>>>Keith
>>
>>Cool.
>>
>>Pardon my ignorance, but when is the big competition again?
>>
>>Will you publish some technical info after the comp? Like what sort of speedup
>>you're getting from 512 processors?
>>
>>Regards,
>>Keith
>
>Everything will be published including logfiles with numbers in it.
>
>i never play unfair. everything will be posted on the diep speedups also in the
>ICGA journal with url where you can find the logfiles (or i'll email them at
>request).
>
>maximum number of addressable cpu's is 508 then some need to be used by other
>dudes who continuesly do stuff. so i hope that isn't 300 cpu's during the
>tournament as then only 200 are left to get used.
>
>I can only do those 500 processor tests probably during the rounds at world
>champs 2003.
>
>The only thing i cannot garantuee is when the logfiles get posted. It will be
>probably around or after the world champs. Not before, but directly after sure.
>
>Most likely the logfiles while playing get posted while it plays. Except perhaps
>the game against the junior team the logfiles will not be posted live, because i
>do know what they do if they see a brilliant line from DIEP in the logfile...
>
>I would be very happy with around 10% speedup.

I've needed a little thought about about your numbers. Am I correct in assuming
10% means: 10% of the max speedup of 500 processors ?

So Diep searches about 50 x faster on this machine ? Nice ! Is that time to
solution ?

BTW, how is your branching factor holding ? I assume it's not possible to stay
below 3, those last few (3-4) plies ?

Tony

>
>But never forget that's actual speedup. that's with a program which also runs
>well at a single cpu machine. zugzwang claimed for example 50% speedup.
>
>but that was with 512 processors and in total 5 ply searches fullwidth were
>performed. he calculated speedup based upon number of nodes at a 5 ply fullwidth
>search.
>
>Imagine that i create a bug in diep that only 1 cpu searches and the rest idles.
>Then my speedup in number of nodes is of course 100%. But my speedup in time is
>1.0 out of 512.
>
>They concluded 50% from that, which is very poor if you consider how little
>nodes a second a single cpu also got with them. I do not see how they could do
>that. Their way of measuring sucked. Deep Blue guessed with a wet finger that it
>was 8% without any evidence at around 30 nodes. Not even their output shows
>number of searches searched.
>
>Hyatt on the other hand claims on a shared memory machine 11.x out of 16 cpu's
>or so. He did not slow down his program 30 times like the zugzwang team did, but
>did some modification to his search results as i have proven in august 2002. you
>still can get the data in a table and look for yourself. All he tried to cover
>up for is probably a factor 2 which he lost somewhere. Still considering the
>fact that he didn't slow down his thing 30 times, it is a very good speed.
>
>Then we have many poor researches. Without exception they managed all to get
>great results, without showing any logfile.
>
>DIEP's output however shows everything. In logfiles are all statistics
>available. local hashhits,globalhashhits, number of nodes needed for each ply
>and for each mainline. number of searches done. number of failhighaborts (1 cpu
>aborting possibly other cpu's as well), how many nodes were done during
>nullmove, etcetera. In short nothing amateuristic where by not showing anything
>you can cover up for having a sucking program.
>
>I have no statistics to hide in that respect. To my sponsor NWO i have already
>written down in the 400 pages or so i wrote to get system time (that doesn't
>only involve nwo but another 6 other organisations), that it is my intention to
>publish all logfiles open and fair. No bad science there.
>
>The NWO of course is an organisation that appreciates this.
>
>Best regards,
>Vincent



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