Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: Eugene's new endgamedatabase code

Author: Eugene Nalimov

Date: 14:45:31 01/25/99

Go up one level in this thread


On January 25, 1999 at 17:11:48, Peter Fendrich wrote:

>In another post Bob mentioned "Eugene's new endgamedatabase code".
>What's thatand are there any improvements compared to the code from Steven J.
>Edwards?
>//Peter

You can download source of the generator and Win32 executables
from ftp.cis.uab.edu/pub/hyatt/TB.

Main advantages of my generator over Edwards' are:
- better indexing schema, so my TBs are approx. 2 times smaller;
  also, better data locality speedups lookups,
- probing code hash chunks of TBs in memory, so you can trade
  RAM for probing speed,
- it supports SMP,
- en-passant captures are correctly handled,
- I generated full set of 5-man (3+2) TBs; you can find it at
  Bobs' site, too. Total size is 22.5Gb.

If I remember it correctly, in the positions with a lot of TB
probes, Crafty with my probing code is ~6 times faster than the
old one (3 times faster because of hashing, plus additional 2x
speedup because of SMP).

Next improvement is pending - on-the-fly TB decompression.
TBs must become 3-5 times smaller with only a small impact on
probing speed. The code is ready and waits for Bob to test it
and incorporate it into Crafty. After that decompression code
as well as compression utility will be available, too.

Eugene



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.