Author: Sune Fischer
Date: 14:21:06 11/06/03
Go up one level in this thread
On November 06, 2003 at 15:55:10, Russell Reagan wrote: I think you are perhaps simplifying it a bit too much, things don't compare that easily. The Opteron is very different in other aspects, like more register and more cache. It is likely one of those that has had a greater influence. Let's wait a while and see some more bitboarders compile and what they get. I suspect Crafty has a bit of a cache problem which might distort the picture ever so slightly, or perhaps DS just badly needed a few more registers, who knows. Also keep in mind that even in a bitboard program not *every* operation is a bitshift, some of us actually do have branches and use a few regular 32bit integers here and there :) -S. >In this thread: > >http://www.chess-archive.com/ccc.php?art_id=310212 > >Gian-Carlo Pascutto reported that his program, Deep Sjeng (compiled for 64-bit >hardware), ran 70% faster on an Opteron, clock for clock. As far as I know, Deep >Sjeng is not bitboard based. > >In this thread: > >http://www.talkchess.com/forums/1/message.html?325912 > >Eugene Nalimov reports that Crafy (compiled for 64-bit hardware) gets 1,761,569 >nps on a 1.8GHz Opteron. On my 2GHz Athlon, Crafty gets 1,230,931 nps. > >(2.0 / 1.8) x 1,761,569 = about 1,957,298 nps on a 2GHz Opteron > >So, clock for clock, Crafty is 1,957,298 / 1,230,931 = 1.59 times faster (60%) >on an Opteron, while Deep Sjeng was 70% faster. I suspect Eugene was using his >magic unreleased compiler also, which probably produces faster executables than >gcc. But that is speculation. > >So either Deep Sjeng is bitboard based, or the expected advantage that bitboard >engines were going to get that non-bitboard engines were not going to get does >not exist. Or I'm overlooking something else. > >Thoughts?
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.