Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: Gandalf HASH notice for all!!

Author: Uri Blass

Date: 02:49:36 01/09/01

Go up one level in this thread


On January 09, 2001 at 05:40:12, Ulrich Tuerke wrote:

>On January 09, 2001 at 05:17:21, José Carlos wrote:
>
>>On January 09, 2001 at 04:55:19, Jouni Uski wrote:
>>
>>>On January 09, 2001 at 04:08:38, Ulrich Tuerke wrote:
>>>
>>>>On January 09, 2001 at 03:09:39, Jouni Uski wrote:
>>>>
>>>>>If I am not complete wrong please note:
>>>>>
>>>>>Because Gandalf is so slow in NPS sense (about 1/4 of many top engines) it needs
>>>>>much less HASH table RAM than other programs and if You give too much HASH it
>>>>>weakens engine! So my recommendation:
>>>>>
>>>>>  500 Mhz PC 32MB
>>>>> 1000 Mhz PC 56MB
>>>>>
>>>>>The readme.txt to use 104MB for >128MB PC is not wise at all.
>>>>>
>>>>>Jouni
>>>>
>>>>I don't see, why "too much" hash could do any harm.
>>>>Uli
>>>
>>>I am not sure may be there is minor bug in hashing code. With 104MB (or similar)
>>>clearing of hash seems to take 5-10 seconds in my PC!
>>>
>>>Jouni
>>
>>  I don't understand why should a program clear the hash table every move.
>
>"Preprocessors" have to this because their eval in the tree depends mainly  on
>the root position. So the hash table becomes invalid - strictly speaking - when
>advancing to another root position. However I thought that Gandalf is a leaf
>evaluater , so it shouldn't be forced to clear the hash table at each move.

Gandalf is a leaf evaluator.

I asked the programmmer about it because this was my impression based on
analysis and I wanted to know if there are no rare cases when it does some root
processing.

Steen replied  me:

Gandalf is a "full-blown" evaluator that doesn't care about
the root position.

Uri



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.