Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: good MP idea?

Author: Tom Kerrigan

Date: 05:05:04 07/31/98

Go up one level in this thread


Would this work on modern computers?
IE, 400 MHz processors with lots of cache?
Seems to me like cache coherency would be a big deal.

-Tom

On July 30, 1998 at 20:28:10, Robert Hyatt wrote:

>On July 30, 1998 at 17:17:05, Tom Kerrigan wrote:
>
>>Memory isn't fast enough to divide up processors by function (e.g., move
>>generation, etc.). It wouldn't make the program any faster.
>>
>>Cheers,
>>Tom
>
>actually it is.  In fact, this is how "hitech" works... one processor
>per chess board square in fact.  And others have played with generating
>moves in parallel, evaluating in parallel, etc.  Where it breaks down is
>once you pass 4 or 8 processors.  IE generating moves with 512 processors
>would be problematic since there are *never* 512 moves to generate, for
>example.  Scalability becomes a serious drawback when you try what is
>commonly called "horizontal multiprocessing" (assuming the tree is a
>vertical entity, horizontal means dividing a single node up into pieces,
>rather than splitting the tree into "vertical slices" and searching each
>part in parallal as I do).
>
> On July 30, 1998 at 16:39:00, Danniel Corbit wrote:
>>
>>>On July 30, 1998 at 14:46:46, Tom Kerrigan wrote:
>>>
>>>>I was just thinking, what if a chess engine was contained in a C++ class?
>>>>It would have a function that starts a little loop that waits for work. When it
>>>>gets work, it starts searching.
>>>>To use it, you make a thread out of this function.
>>>>Then, when you want to write an MP program, you make several copies of this
>>>>class and several threads running the respective loops.
>>>>The threads, being contained in the classes, don't bother each other, except to
>>>>request work.
>>>>Comments? Suggestions?
>>>I think it is a very good idea, but I might scale it down a bit.  For instance,
>>>make the class be a move generator.  Make another class that is a position
>>>evaluator.  The hardest part will be to write the coordinator so that no work is
>>>duplicated and so that resultsare properly synchronized.



This page took 0 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.