Author: Sean Empey
Date: 14:38:45 07/14/04
Go up one level in this thread
On July 14, 2004 at 17:15:52, Omid David Tabibi wrote: >On July 14, 2004 at 17:10:13, Matthew Hull wrote: > >>On July 14, 2004 at 17:03:33, Omid David Tabibi wrote: >> >>>On July 14, 2004 at 17:00:04, Matthew Hull wrote: >>> >>>>On July 14, 2004 at 16:53:39, Omid David Tabibi wrote: >>>> >>>>>On July 14, 2004 at 16:44:00, Peter Berger wrote: >>>>> >>>>>>On July 14, 2004 at 12:56:10, Omid David Tabibi wrote: >>>>>> >>>>>>>On July 14, 2004 at 12:34:18, Peter Berger wrote: >>>>>>> >>>>>>>>On July 14, 2004 at 12:28:29, Omid David Tabibi wrote: >>>>>>>> >>>>>>>>>On July 14, 2004 at 12:19:24, Peter Berger wrote: >>>>>>>>> >>>>>>>>>>On July 14, 2004 at 11:41:04, Omid David Tabibi wrote: >>>>>>>>>> >>>>>>>>>>>On July 14, 2004 at 11:38:31, Peter Berger wrote: >>>>>>>>>>> >>>>>>>>>>>>On July 14, 2004 at 11:26:47, Omid David Tabibi wrote: >>>>>>>>>>>> >>>>>>>>>>>>>On July 14, 2004 at 11:12:14, Fernando Villegas wrote: >>>>>>>>>>>>> >>>>>>>>>>>>>>Not at all, Omid >>>>>>>>>>>>>>If you already have a parallel engine you should run it into a >>>>hardware capable >>>>>>>>>>of getting all its power. >>>>>>>>>>>>> >>>>>>>>>>>>>I understand that you are going to provide the hardware, right? >>>>>>>>>>>>> >>>>>>>>>>>>>It is not something personal; next year I will have the needed >>>>hardware, but >>>>>>>>>what about others? Deep Sjeng and ParSOS were also >>>>parallel engines, but ran on >>>>>>>>>single processor not because they >>thought >>it was better, but because they did >>>>>>>>>not have access to a >>fast >>multiprocessor machine. >>>>>>>>> >>>>>>>>>>>> >>>>>>>>>>>>I wonder what except the results changed from two weeks ago to now to >>>>make you >>>>>>>>imply this is an unfair event and go on raving about it ?! >>>>>>>>>>>> >>>>>>>>>>>>Weren't you even one of the organizers? >>>>>>>>>>> >>>>>>>>>>>Yes, and I complained loudly about it even before the event. >>>>>>>>>> >>>>>>>>>>Actually I still think this is argueing with hindsight. Diep and Crafty >>>>finished >>>>>>3rd and 4th, a result that surprised some of the present >>>>programmers. >>>>>> >>>>>>>>>>It seemed to concern no one last year when it was only the >>professionals >>who >>>>>>came with superior hardware. >>>>>>>>>> >>>>>>>>>>To quote another programmer from memory: "I typically get 80% in tests >>>>against >>>>>>Crafty, so on a Quad it might get 30% or sth like that ". >>>>>>>>>> >>>>>>>>>>And we don't know how the results would have looked like in a single >>CPU >>event >>>>>>either - before the tournament it was "Crafty is a miserable >>>>program that I can >>>>>>beat on any hardware" (simplified and no quote) - >>>>>>>>> >>>>>>>>>This quote is not from me. >>>>>>>> >>>>>>>>And I didn't imply any different. >>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>>>at least one part of this >>>>>>>>>>statement turned out to be untrue. >>>>>>>>>> >>>>>>>>>>Maybe the hardware impact is a little overrated in this discussion >>>>anyway. Jonny >>>>>>on a PIV2.8 e.g. nearly finished Junior on a Quad. >>>>>>>>> >>>>>>>>>You want to measure the hardware impact, just do the following: >>>>>>>>> >>>>>>>>>Run the Crafty benchmark at a fast single processor machine, and also on >>>>the >>>>>quad machine: >>>>>>>>> >>>>>>>>>ratio = (benchmark on quad) / (benchmark on single proc) >>>>>>>>> >>>>>>>>>(the ratio would be about 4) >>>>>>>>> >>>>>>>>>Next, for each move of Crafty in the tournament, divide the thinking >>time >>by the >>>>>'ratio' above, to get a new time: >>>>>>>>> >>>>>>>>>time2 = (original time spent on the move) / ratio >>>>>>>>> >>>>>>>>>Now just count how many times Crafty changed its PV after 'time2'... (In >>>>other >>>>>words, how many times Crafty changed its PV after thinking for 1/4 >>>>of the time >>>>>on the move.) >>>>>>>> >>>>>>>>This test sounds more scientific and logical than it is. You also would >>>>have to >>>>identify the moves that would make any difference to the result >>of >>the game. >>>> >>>>>>>>I can easily reproduce all critical moves of the Falcon-Crafty game on my >>>>>>>>notebook for black. I already asked you in another message if more time >>>>would >>>>have made any difference for Falcon for two of its critical >>mistakes >>- you >>>>didn't answer yet. >>>>>>> >>>>>>>Just count the number of times Crafty changed the PV after 1/4 of its >>>>thinking >>>time (including pondering), and see how many of them were >>critical, >>and >>>prevented a loss. >>>>>>> >>>>>>>You will find many of them. Here is one I remember clearly: After Falcon's >>>>>>>...Ra5 in the endgame, Crafty wanted to repeat the position at first >>(score: >>>>>0.00). It thought for a long time, and then changed the PV to >>other move, >>which >>>was winning. But you will find many other moves in the >>earlier stage >>of the >>>game, which would have resulted in a loss were they >>played (after >>thinking for >>>1/4 of the time). >>>>>> >>>>>>I think you maybe misunderstood me here because of the heat of the >>>>discussion. >>That I can easily reproduce Crafty's moves on my notebook >>doesn't >>mean that all >>its moves were found fast and easily :). >>>>>> >>>>>>From memory there were two moves in the tournament where Crafty changed its >>>>mind >>very late and that turned out to be of big importance. >>>>>> >>>>>>Kb6 (or whatever the move after Falcon's Ra5, no surprise that we both >>>>remember >>this one) >>>>> >>>>>OK, so at least you agree that without the 4x hardware advantage Crafty >>>>wouldn't >have got more than a draw. >>>>> >>>>> >>>>>> and g5 in the game against Diep. >>>>>> >>>>>>In case there were other moves like that, I am at least not aware of it. >>>>>> >>>>>>I expect Bob to offer Crafty's logfiles for download soon as he did for >>>>cct-6, >>so maybe we should delay this discussion until we can just discuss >>the >>real data >>( I don't have access to the Opteron anymore). >>>>>> >>>>>>I would still be interested to know about the critical points from >>Falcon's >>>>side; Ra5 is a trial to avoid repetition - you have to search very >>deep to >>>>dismiss it. >>>>> >>>>>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, 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? >>>> >>>> >>>> >>>>Why don't you just test it. Download crafty19.15 and setup the appropriate >>>>time controls for each side and start from some move in the actual game. >>>> >>>> >>>>Then we won't be in fantasy land anymore, but in the land of fact. >>> >>>It is not fantasy. During the actual game Crafty found the correct move in the >>>endgame after a very long search (previous best move was threefold >>repetition). >Peter was the operator, and has said the same in the post above. >>Quoting him: > >>>"From memory there were two moves in the tournament where Crafty changed its >>>mind very late and that turned out to be of big importance. Kb6 (or whatever >>the >move after Falcon's Ra5, no surprise that we both remember this one)" >> >> >>No, I meant that Falcon could find _winning_ lines, not just drawing lines. > >I will try the game to see if there was a clear winning line. But it is clear >that on equal hardware white would not have lost the game. That's not clear until you can also prove Crafty would not have found that move on a single processor. And Falcon could actually win the game. You need data to back that claim up. -Sean > > > >>Remember that Boris said many times that the game was over in favor of white. >>So white should have won. Give Falcon equal time as crafty, and long time to >>simulate 4x opterons. >> >>Then we should know if you would really have won that game with equal hardware. >> >> >>The other experiment is to substitute Junior for Falcon on the slow hardware >>setup and see if Junior also cannot win on uniprocessor. >> >>> >>> >>>> >>>> >>>>:) >>>> >>>> >>>> >>>>> >>>>> >>>>> >>>>>>And Ra8 is probably not about search at all. >>>>>> >>>>>>Peter
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