Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: Crafty SMP questions.

Author: Slater Wold

Date: 16:13:21 08/05/03

Go up one level in this thread


On August 05, 2003 at 18:38:51, Robert Hyatt wrote:

>On August 05, 2003 at 17:30:51, Matthew Hull wrote:
>
>>Does Crafty scale above 4 processors?  For example, could crafty utilize all the
>>CPUs on an IBM pSeries 690 7040-681T 32-way?
>>
>>http://www-132.ibm.com/content/home/store_IBMPublicUSA/en_US/eServer/pSeries/high_end/690.html
>>
>>MH
>
>
>I didn't have time to look closely.  But it is most likely a NUMA platform,
>which means that Crafty as it exists now is not going to work well on it.  NUMA
>machines require careful attention to what is put where in memory, so that
>often-used data is as close to the physical processor (in terms of access
>latency) as possible.  The current implementation of SMP in Crafty is based
>on pure SMP, where memory is simply shared.
>
>If I ever have time to fiddle with a NUMA machine, I'll probably look at
>fixing the major issue, which is to put split blocks close to each processor,
>and when giving a specific processor a tree to search, using a split block that
>is _close_ to it.

I really don't think it is a NUMA machine.

"Advanced symmetric multiprocessing (SMP) up to 32-way", is how the exactly
describe it.

And when you go to their 'Clusters' section, this machine isn't mentioned.



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.