Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: RAM , Hash tbl. and processor speed

Author: Aaron Gordon

Date: 02:30:04 03/29/03

Go up one level in this thread


On March 28, 2003 at 17:18:54, Tom Kerrigan wrote:

>On March 27, 2003 at 20:06:03, Aaron Gordon wrote:
>
>>from 1GHz as you said in your previous post. Now, for memory speed you may only
>>get 2-10% doubling memory speed with large hash tables (256mb+). With sub-32mb
>>hash tables you will see next to nothing, though.
>
>Interesting. Maybe I thought that memory speed didn't affect chess programs
>because memory speed changes very gradually. I mean, it's unlikely that you'd be
>comparing a machine with 133MHz memory to one with 66MHz memory... if doubling
>the speed gives you a 2-10% increase, then a typical increase like 100 -> 133MHz
>would give you 0-3%...
>
>>>It's not clear to me that the "fullness" of a hash table is a significant
>>>metric. It's the usefulness of the entries in the table that counts. Do you get
>>>better scores (or faster times to solutions) on test suites with really big hash
>>>tables?
>>I haven't done any test suite testing, just numerous games on FICS. With smaller
>>hash tables it seems the engine just looses it's "oomph" after the hashtable is
>>full. I see a LOT more draws when I use a hashtable 128mb or lower vs 256 and
>>more. I mainly use Deep Fritz 7 and Fritz 8, so you may see some different
>>results with other engines. Generally from what I've seen though when using a
>>fast CPU with tons of hash the engine just seems to pack more of a punch.
>
>Not to demean your observations, but this seems like the archetypical situation
>for selective observation... There are a lot of posters here who will say that
>program X is much stronger than program Y because of some games they watched,
>but when a long match is done, X draws or loses to Y...
>
>-Tom

I rarely do long games do 3 1 to 5 3 blitz is about as much as my engines will
see. From what I've seen though if I use a smaller hash size the engine just
won't play as well. The difference isn't night & day though.



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.