Author: Frank Quisinsky
Date: 09:49:35 09/19/00
Go up one level in this thread
On September 19, 2000 at 11:50:02, Robert Hyatt wrote: >On September 19, 2000 at 11:05:01, Frank Quisinsky wrote: > >>On September 19, 2000 at 10:16:19, Robert Hyatt wrote: >> >>>On September 19, 2000 at 01:37:39, Frank Quisinsky wrote: >>> >>>>Hello, >>>> >>>>which program can solved 9/14 positions (I think no program can solved so many >>>>positions). Gandalf results, no 0 or 1 seconds results: >>>> >>>>01. 0578 seconds >>>>02. 0980 seconds >>>>03. 0386 seconds >>>>04. 0449 seconds >>>>05. 0205 seconds >>>>06. 0252 seconds >>>>07. 0711 seconds >>>>08. 0486 seconds >>>>09. --- >>>>10. --- >>>>11. 1151 seconds >>>>12. --- >>>>13. --- >>>>14. with the right move in ~ 32 minutes ! >>>> >>>>BS2830 = 2667 ELO >>>>LCTII = 2730 ELO >>>> >>>>In my eyes is Gandalf 4.32f the strongest program for analyses and maybe >>>>the stronges chess programm in the world ? >>>> >>>>Best >>>>Frank >>> >>>This has very little to do with how "strong" an engine is compared to others. >>>It only means it solves _this_ problem set faster. >> >>Yes this is right. >> >>In my News Ticker I have 250 Gandalf games with longer time controls and ponder >>! >> >>I am sure, I made a lot of tests with Gandalf in the last time. I think for >>tactical and middelgame analyses is Gandalf a very good engine. OK, I know not >>all commercial programs but I know a lof of results. >> >>BTW: >>Crafty played very good against the playing style from Gandalf ! >> >>A questions to Crafty: >>I see that Crafty 17.13 is not faster then Crafty 17.11 but the new SMP version >>is faster. >> >>At the moment is the dual technic factor 1.8. Do you think that factor 1.9 or >>1.95 is possible ? > >At times, 2.0 is possible. But even 1.8 is not always going to happen. I >even have a position or two where 2 processors are _slower_ than one. > > >> >>I have interest to get more information why is not more then factor 1.8 >>possible. I think a very interesting message for my News Ticker because more and >>more persons have interest to buy a dual system an I think this is a interesting >>question about SMP. > > >Because move ordering is not perfect. If you start a parallel search at a >ply where only one move needs to be searched, the extra processor is searching >a part of the tree that a single processor program would not search due to an >alpha/beta cutoff. Since move ordering is not perfect, it is impossible to >accurately choose a position where all moves have to be searched, vs a position >where only one move needs to be searched. > >As I have mentioned before, in Crafty, I am about 92% right. That is, if I am >going to get a beta cutoff, 92% of the time it happens on the _first_ move >searched at a ply. Unfortunately, that 8% where it is wrong is a real killer >to parallel performance. > >Hence my 30% per processor overhead estimate. 1cpu = 1.0 speedup. 2cpu = 1.7 >speedup, 3cpu = 2.4 speedup and 4 cpu = 3.1 speedup. All rough averages, actual >numbers will vary wildly. Thanks Robert, I added your message in my News Ticker. Best Frank > > > > >> >>See here (little zip file, Crafty bench results on dual and single PIII): >>http://amateurschach.in-trier.de/schach/download/sonstige/crafty_bench2.zip >> >>Frank
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