Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: speedup of cray blitz as published in 1997

Author: Vincent Diepeveen

Date: 08:24:16 09/25/01

Go up one level in this thread


On September 25, 2001 at 09:56:52, Robert Hyatt wrote:

>On September 25, 2001 at 07:28:17, Vincent Diepeveen wrote:
>
>>On September 25, 2001 at 00:40:53, Robert Hyatt wrote:
>>
>>>On September 24, 2001 at 23:45:30, Dave Gomboc wrote:
>>>
>>>>On September 24, 2001 at 22:30:26, Vincent Diepeveen wrote:
>>>>
>>>>>Hello,
>>>>>
>>>>>Here written down speedups as claimed by a guy called R. Hyatt
>>>>>by cray blitz for 24 different positoins as they occured in
>>>>>a game:
>>>>>
>>>>>pos  speedup
>>>>>1     2.0
>>>>>2     2.0
>>>>>3     2.0
>>>>>4     2.0
>>>>>5     2.0
>>>>>6     2.0
>>>>>7     1.9
>>>>>8     2.0
>>>>>9     2.0
>>>>>10    2.0
>>>>>11    2.0
>>>>>12    1.9
>>>>>13    1.9
>>>>>14    2.0
>>>>>15    2.0
>>>>>16    1.9
>>>>>17    1.7
>>>>>18    1.8
>>>>>19    2.0
>>>>>20    2.0
>>>>>21    2.0
>>>>>22    1.9
>>>>>23    2.0
>>>>>24    2.0
>>>>>avg   2.0
>>>>>
>>>>>So YOU, Robert Hyatt, claims in an OFFICIAL magazine,
>>>>>called ICCA journal march 1997,
>>>>>an AVERAGE speedup of 2.0 with cray blitz at 2 processors.
>>>>>
>>>>>Now i claim the same with DIEP if i'm not using dangerous
>>>>>extensions (which btw are turned on by default).
>>>>>
>>>>>It appears you hadn't turned them on either (smart guy
>>>>>to publish only speedups without dangerous extensions and only
>>>>>tell in 2001 that you hadn't turned them on).
>>>>
>>>>2.0 isn't a problem, it's >2.0 that gets people up in arms.
>>>>
>>>>Dave
>>>
>>>
>>>It isn't even 2.0...   I don't have the paper handy now but I seem to recall
>>>that it was 1.9.  Certainly it isn't 2.0 just by inspecting the numbers he
>>>gave...
>>>
>>>And the 4 8 and 16 processor tests were worse.  But comparing them to crafty is
>>
>>When i tested with 4 i also never got > 4.0 with normal diep versions,
>>so very consequent with Cray Blitz, of course there are good reasons
>>why my speedup tests i get 2.0 in practical game
>>play at tournament level versus cray blitz 2.0
>>in practical game play getting the same at 2 processors.
>>
>>Bob explained me quite clearly how he had done things in Cray Blitz,
>>my entire algorithm is based upon that of course!
>>
>>I am sure that if cray blitz would run on 2 faster Cray processors,
>>or simply run longer, that then all its findings will be similar to
>>my findings!
>
>
>
>Why don't you look at that JICCA article.  Those _were_ long searches.
>Since I originally ran on 16 processors, I stuck with those results and
>backed up to 1, 2, 4 and 8 processors.  the 1 processor searches took hours
>at times.  The 2 processor tests were _not_ just 3 minute searches.  They
>were huge.

R=1, futility, 200Mhz things and most likely a relatively bad
tuned evaluation, when compared to todays standards.

>
>
>>
>>>very hard because of the different approaches to almost everything from move
>>>ordering to search algorithm...
>>
>>Crafty is recursive, only when you have your own program parallel you
>>will understand what a big difference in parallel speedup this means
>>for DIEP + Cray Blitz. I do not know whether Fritz is recursive. It's
>>assembly, so perhaps Frans can somehow avoid recursive problems in assembly
>>in a smart way.
>
>
>
>I have done it both ways.  The advantages to non-recursive are only programming
>issues, _not_ efficiency issues. There is nothing I could do in CB that I can't
>do in Crafty, if so inclined.  I chose to avoid the extra complications for the
>moment, but it _was_ a choice, not a requirement.



This page took 0.01 seconds to execute

Last modified: Thu, 15 Apr 21 08:11:13 -0700

Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.