Author: Robert Hyatt
Date: 19:19:12 07/14/04
Go up one level in this thread
On July 14, 2004 at 17:14:30, Omid David Tabibi wrote: >On July 14, 2004 at 17:07:37, Peter Berger wrote: > >>On July 14, 2004 at 16:53:39, Omid David Tabibi wrote: >> >>>One iteration deeper Falcon switches to the other move which results in actual >>>threefold repetition. >>> >>>In other words, had Crafty not had the hardware advantage it would have missed >>>the win, >> >>Most probably correct, agreed - although of course this is not about hardware >>advantage, but just about its own hardware . I could try it on my notebook, but >>I will just have a look at the logfile later. >> >> >>> and had Falcon had the 4x hardware it would have found the correct draw >>>(and with that hardware advantage probably also found a correct winning line). >>>Right? >> >>That's speculation when it is about the win. > >But no speculation as to the draw on equal hardware (whether both ran on 4x or >1x). > > >>You have access to Falcon - show me >>a winning line found by it with more time. The game was very interesting; I >>would be interested to discuss and analyze it. > >I will surely analyze the game in detail. It is very hard to believe that white >did not have a win there. > > > >> >>Btw, you play with this 4x number very carelessly IMHO. *For Crafty* a Quad >>Opteron is indeed about four times faster than an overclocked AMD2.5GHz 32 bit >>system, but that's the result of programming effort. While Shredder seemed to >>get a very decent speedup, the same was not necessarily true for Fritz and >>Junior, judging by NPS, although I of course can only compair with commercial >>versions - Frans Morsch at least seemed to be impressed by Crafty's speedup. >> >>You probably will have quite some work to do to reach similar speedups as Crafty >>once you get your hands on a Quad Opteron :) > >I say "at least 4x", because each of those Opteron processors was faster than my >2.0GHz AMD 64. In fact I think it was quite more than 4x... Bad math. Here is the correct math. I had 4 X 2.4ghz. You had 1 X 2.0ghz. My SMP speedup is about 3.1X. that gives me 3.1 * 2.4ghz effective speed. IE 7.44ghz. I also lose another 10% overall as that machine did not have all the working NUMA kernel stuff, so that drops to about 6.7ghz effective speed. The difference was really about 3.3x at best... Those with numbers that anyone can verify. > > >> >> >>>>And Ra8 is probably not about search at all. >> >>Have you tried this one too ? > >No, but that was not the losing move (even though it was clearly a bad move). >Ra5 lost the game, when a draw could have been easily achieved by threefold >repetition.
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