Author: Uri Blass
Date: 07:40:37 08/31/03
Go up one level in this thread
On August 31, 2003 at 10:20:36, Anthony Cozzie wrote: >On August 31, 2003 at 02:21:03, Steven Edwards wrote: > >>The portable C++ CT toolkit has classes for describing positions either with or >>without bitboard representation in use. Here are the results of running both of >>them for enumerating the 119,060,324 movepaths of length six from the initial >>position on a 800 MHz G4 PPC notebook: >> >>Non bitboard: >> >>Frequency 1.07069 MHz >>Period 933.98 ns >>Cycles per node 747.184 >> >>Bitboard: >> >>Frequency 342.689 KHz >>Period 2.9181 us >>Cycles per node 2334.48 > >This is why abstracting the very base datastructures is a bad idea. Your >program is searching 340knps with no eval function, no pruning, no transposition >table lookup, etc. If someone writes an engine based on your bitboard code it >will probably search 100knps even with just a beancounter eval. Why do you think so? maybe making move and calculating all the attack information is the expensive part and from 342 knps you will go down to 300 knps. Abstraction >always costs you in speed; in a chess program you just can't afford a 2x speed >decrease with no gain (other than being able to easily modify your code) > >anthony I think that it is a decision of the programmer. 2x speed decrease is not so much. The gap between most programs and the top program is clearly more than 2:1 and most amateurs are weaker than the commercial program even with time handicap of 3:1 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.