Author: Dieter Buerssner
Date: 13:26:52 01/16/03
Go up one level in this thread
On January 16, 2003 at 15:41:16, David Rasmussen wrote:
>I only have 256MB RAM in this machine. That might be part of the problem. If
>that is the problem, is there anyway to confirm it? I guess I could look at the
>Windows Task Manager performance tab, and see how much cache is used, or
>something.
For example. Also, how much of this memory is free? (not used for hash, egtb
cache, decompression tables, ...).
Since not too long, I have 512 MB RAM. For any middlegame position, I can use
450 MB hash. When I want to analyze some endgame position, that will have many
TB-accesses, I would use much less, to give the OS more space for cache.
Before I had only 56 MB RAM (8 of 64 was used for onboard graphics). Then again,
I did it similar. For middlegame positions, 40 MB hash worked fine. For endgame,
I often used half of it or less.
>>Another thing - don't install all TBs. If your engines has problems with missing
>>promotion cases, you must be careful to select them. Don't define T41_INCLUDE.
>>
>
>What is T41_INCLUDE?
It is a preprocessor symbol at the start of tbindex.cpp. Eugen writes about it:
You have to define the following macro:
[...]
- T41_INCLUDE - if you want to probe any 5-man 4+1 table (e.g. KPPPK);
if you will not ever probe those tables (I suppose
most chess program will never do that), you can save
some space by not including corresponding code and
enumeration tables;
>Also, I have _all_ 3-5 TBs, all 7.1GB of them. That's ok, isn't it? Also, I
>don't understand what you mean by problems with missing promotion cases.
The performance can be better, when you do *not* have all TBs installed. I
think, quite a few are practically useless (at least, when you don't care about
finding a mate fast, instead of showing a big score). But, when you have say
KRPKR installed, and KRQKR not, your engine may refuse to promote the pawn. You
will find many discussions and solutions for this in the CCC archive. In more
detail, the problem is described http://www.aarontay.per.sg/Winboard/egtb.html,
see A.9.
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