Computer Chess Club Archives


Search

Terms

Messages

Subject: crafty favouring P4 nowadays?

Author: Vincent Diepeveen

Date: 06:34:28 03/06/03

Go up one level in this thread


On March 06, 2003 at 09:16:22, Vincent Diepeveen wrote:

I been searching in crafty source code for Lock() and see now that the inline
assembly that used to be there for it, is REMOVED. This is shocking!

It has been replaced by slow system functions instead which simply make the
thing slower. This is what i call the usual scientific idea of making a program
slower in order to get a better speedup in this case for SMT/HT?

Especially with coming Opteron NUMA systems in mind it is of course a very bad
idea to do this.

Nothing as weak as system functions, and crafty *does* do a big number of
searches each second each cpu, so locking is a very important thing to not slow
down!

>the windows makefile doesn't work by default for compilers
>when you turn on:
>
>COPTS    = /DSMP /DCPUS=2
>
>the problem of that is that then in egtb.cpp the function Lock is not defined.
>Of course i know how to solve it, but it should be in egtb.cpp simply.



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.