Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: Question for Hyatt

Author: Robert Hyatt

Date: 02:38:33 08/13/98

Go up one level in this thread


On August 13, 1998 at 01:35:03, Bela Andrew Evans wrote:

>Hi Bob --
>
>some quick questions for you.  If a good assembly language programmer took your
>crafty chess engine and rewrote it in machine language, what kind of speedup
>would you estimate on different platforms, or specifically, the PCs of today?
>50% faster, 100%, 200%? Or would the speedup be minimal?
>
>And how long would you estimate such a project would take?
>
>Thanks in advance, Bela

Very difficult to answer.  With Cray Blitz, Harry Nelson and I did this.  But
we did two things simltaneously:  we converted fortran to assembly, but we also
modified algorithms and ideas globally to fit the cray architecture.  We ended
up with a program 4.5 times faster.

Doing this on the PC would take a lot of time, because it isn't just an issue of
converting to assembly, it is also an issue of studying the X86 platforms and
modifying the algorithms and data structures to better fit that machine.  And
that would be difficult when you look at how frequently the processor changes,
from basic L2 cache speed/size, to the pipeline approach, to superscalar
execution, even to some supporting register renaming to give you effectively a
large group of registers...

The speedup would depend on how "deep" someone wanted to go.  IE, on the Cray,
we moved the chess board into a single vector register and *never* touched that
so the board was always instantly available.  There were other things done like
this (the repetition list and some things like that).  IE this is *really*
algorithm-specific/architecture-specific matching.  And when Merced drops out
year after next, the architecture will be so different this would get thrown
away...



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.