Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: Hash size - when is enough enough ?

Author: William Penn

Date: 06:01:29 04/20/04

Go up one level in this thread


On April 20, 2004 at 08:17:35, Ray Banks wrote:

>Is there a "sweet spot" for the size of the hash tables, i.e. a point beyond
>which increasing it any further has negligible effect on strength ?
>
>Does an incraese from say 128MB to 256MB have a noticeable effect, and what
>about beyond 256MB ?

It depends... :)

I only use chess software in Infinite Analysis mode, calculating for at least
one (1) hour for each position, so all of my comments are related thereto...

I have 1GB installed RAM, and usually use the maximum hash allowed by my
multitasking environment. Generally I can use up to about 832MB hash and Windows
XP Home will still let me run Internet Explorer, Outlook Express, etc without
serious handicap (excessive swapfile activity). Sometimes I lower the process
priority of the engine (Ctrl-Alt-Delete, rightclick the engine process) one
notch if the system is too sluggish, which is most likely to happen in endgames
when tablebases are involved.

In the latter case (endgames with all 3-4-5 piece tablebases), I find it
necessary to reduce hash size a lot in order to maintain good engine speed, and
I typically use 192MB or 256MB hash in endgame positions. It works best that way
for me. The alternative is slow engine speeds and a lot of hard drive chugging.
WP



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.