Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: For the Record: Effects of Larger Hash Tables

Author: Andreas Guettinger

Date: 08:56:42 12/03/05

Go up one level in this thread


On December 03, 2005 at 11:01:46, Paul Jacobean Sacral wrote:

>I would appreciate a couple of clarifying remarks as well, because this is a
>topic that's difficult to understand if you are not a progammer. Bacically, I
>was studying explanations of this in the past but didnt't understand all of it,
>and also do not remember all of it.
>
>My question is:
>
>How come that some solving times of test positions are worse (longer) with
>bigger hash tables, than with smaller hash tables?
>
>Yours truly Paul J. Sacral

Can you give an example?
The size of the hashtable should not make a considerable difference in solving
time, except if the engine clears the hashtable in analysis mode at the
beginning of the search, which could take 1 or 2s on slow hardware. (Note during
normal gameplay hastables usually don't get cleared.)
Per position (in the search tree) it takes normally 1 (written ONE) probe per
hashtable, doesn't matter if the hashtable is 1Mb or 1Gb.
As a banal example, if you have a file register in your office, and you want to
lookup file no. 56, it doesn't mater if you have 100 or 1000 files stored, you
just walk to the shelf and take file number 56.

regards
Andy



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.