Author: Gerd Isenberg
Date: 00:06:21 09/13/03
Go up one level in this thread
On September 12, 2003 at 20:58:33, Vincent Diepeveen wrote: >On September 12, 2003 at 17:00:25, Gian-Carlo Pascutto wrote: > >minimum number of bits to store somehow either by index or non-index is > >48 bits (1 = pawn, 0 = no pawn) + 16 bits ( 1 = white, 0 = black ) = 64 bits. > >So that is going to be massive overwriting. of similar structures at the same >adress. Very poor for hash %. Why do you reply to Gian-Carlo and not to me? Hitrates with (whitePawns-blackPawns)%49981 are not that bad. Show me some different pawn positions, which map to the same 48-bit white-black difference... > >Skip bitboards. Not in geneneral of course - maybe for this purpose. That's not a bitboard issue - it's about using power of two sized tables. > >Just use Zobrist and AND. Yes, i will try it and report the speed gain... > >DIEP's pawnhashtable is like 4MB anyway and never bigger. I never understood >those large sizes for pawn hashtables. Soon i can get rid of the thing >completely when the last couple of hundreds of patterns get extra conditions, so >getting difficult to cache. > I found a range of 32-64K entries appropriated, results in the memory size you mentioned. Due to fast bitboard routines to get all kinds of pawn patterns, i'm also thinking about throwing out pawn hash tables... At least i will not store easy to compute patterns like passed and backward etc. into pawn hash anymore. Gerd <snip>
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.