Author: Robert Hyatt
Date: 14:19:06 10/31/99
Go up one level in this thread
On October 31, 1999 at 16:49:30, Amir Ban wrote: >On October 31, 1999 at 14:20:23, blass uri wrote: > >>On October 31, 1999 at 13:57:54, Robert Hyatt wrote: >> >>>On October 31, 1999 at 11:53:38, blass uri wrote: >>> >>>>On October 31, 1999 at 10:12:06, Amir Ban wrote: >>>> >>>>>On October 30, 1999 at 17:52:02, Christophe Theron wrote: >>>>> >>>>>>On October 30, 1999 at 08:22:00, Enrique Irazoqui wrote: >>>>>> >>>>>>>I have played 2 matches at game/5 between Tiger 12.0 and Crafty 16.18 as an >>>>>>>engine for Fritz. >>>>>>> >>>>>>>Crafty played on a PIII-500, 64MB hashtables, the Nalimov tablebases that come >>>>>>>with Fritz and the General book of Fritz 5 built after games of 2500+ players. >>>>>>> >>>>>>>Tiger 12.0 played on a PII-300, 32MB hashtables and the small book of Tiger 11.7 >>>>>>>with only 35000 positions. >>>>>> >>>>>>Oops... Not exactly. >>>>>> >>>>>>This book indeed comes from the first versions of Tiger 11.x but it contains >>>>>>only 7682 moves. >>>>>> >>>>>>This is 35 times smaller than the current book provided with Tiger 12.0. >>>>>> >>>>>> >>>>>> >>>>>>> I used this book to compensate for Crafty not using >>>>>>>its own. It was not uncommon to see Tiger out of book after 2, 3 or 4 moves. I >>>>>>>don't think that the book gave Tiger any kind of advantage. >>>>>>> >>>>>>>In the first match, Tiger won 25-13, +19 -7 =12, scoring 65.7% >>>>>> >>>>>>Wow! What elo rating difference would that mean? >>>>>> >>>>>> >>>>>> >>>>>>>The second match was played under the same conditions, except that Tiger had PB >>>>>>>off. In this second match, Tiger won 23-21, +16 -14 =14, scoring 52.2%. >>>>>>> >>>>>>>Going back to the discussion of a few weeks ago about PB on/off, these 2 matches >>>>>>>seem to indicate that PB off is not more detrimental than what could be expected >>>>>>>by just not using the usual 50% of the opponent's time. >>>>>>> >>>>>>>The delay in transmitting the moves through auto232 is almost 3 seconds/move for >>>>>>>the dos driver and about 2/10 for the windows driver. Considering that the >>>>>>>average in these matches is 79 moves/game, each game lasted 14 minutes instead >>>>>>>of 10. Assuming that both programs guessed 50% of the opponent's moves, Tiger >>>>>>>and Crafty used 9.5 minutes/game (5 + 4.5) each with PB on, while in the second >>>>>>>match Tiger used 5 minutes/game. It is as if Tiger would have played the first >>>>>>>match on a P300 and the second on a P150. All this mess (sorry) makes the >>>>>>>results of both matches quite coherent. >>>>>>> >>>>>>>I tried all this PB on/off thing in a different way. Didzis plays with 2 >>>>>>>programs on one machine and PB off. I replayed with 2 machines one of his games >>>>>>>Tiger-CM6K and both programs played the same moves. >>>>>>> >>>>>>>So it seems that for some programs playing with PB off has no other effect than >>>>>>>having less time to compute. >>>>>> >>>>>> >>>>>>Also it seems that a crippled Tiger is still better than a full strength Crafty >>>>>>(PII-300/small book against PIII-500). >>>>>> >>>>>>And it seems that a crippled crippled Tiger is still at least as strong as a >>>>>>full strength Crafty (PII-300/PB off/small book against PIII-500). >>>>>> >>>>>>I find this interesting as some time ago Bob was laughing at me because I'm >>>>>>still using a 386sx20 for some of my tests and algorithmic improvements. >>>>>> >>>>>>I would not be surprised if Chess Tiger 12.0 on PII-300 was able to stand Crafty >>>>>>on a Quad-Xeon. After all that would only be a 4x speed advantage for Crafty. :) >>>>>> >>>>>> >>>>>> >>>>>> Christophe >>>>> >>>>> >>>>>That's approximately the speed advantage in crafty vs. ban on ICC (that is, >>>>>pre-noplaying and censoring): >>>>> >>>>>4 x 450 MHz at 5 + 3 inc vs. 2 x 350 MHz at 5 + (-1) (that's my setting because >>>>>I'm manual). If the game lasts 60 moves that translates to: >>>>> >>>>> >>>>> (1800 MHz * 8 min) / (700 MHz * 4 min) > 5 >>>> >>>>It is not exactly the case because crafty has not >5 times advantage in >>>>pondering. >>>> >>>>Crafty can ponder 8 minutes when Junior can ponder the time that it does not >>>>play (16-4 minutes=12 minutes) >>>> >>>>Uri >>>> >>> >>>it is all bad math. The quad xeon runs (generally) a little over 3x faster >>>than a single xeon would. There are many positions where it runs 4x faster, >>>there are some where it is actually slower than a single processor. >>> >>>But in general, it is 3x faster. Amir is running on a dual 350, which is fairly >>>close to 1/2 the xeon. The speed advantage is a little over 2, assuming his >>>speedup for 2 is similar to mine. I have no idea how he would conclude anything >>>greater. >>> >>>If he plays someone on a single cpu at 800 mhz, how much faster is that machine >>>than his? I get 800/350 as a quantum estimate. But I would want benchmark >>>numbers to be really happy, because the 800mhz box might have a memory bandwidth >>>problem. Or a 133mhz bus advantage. >> >>It is more than 800/350 because the fact you play manually is a disadvabtage. >>The fact that you can use the permanent brain does not fully compensate for the >>time advantage. >> >>simple math say if you assume ponder guessing of 50%,8 minutes/game(Junior is >>using only 4 minutes for playing) >>and every player is using 1/2 of the time that it does not use for playing and >>correct in pondering. >> >>Junior is using 4 minutes+1/2*12 minutes=4+6=10 minutes. >>crafty is using 8 minutes+1/2*8 minutes=12 minutes. >> >>This is practically more than 12/10 time advantage because >>it is better to use x seconds for every move than to use x/2 seconds when you >>are wrong in pondering and 3x/2 when you are right in pondering. >> > >Your argument is flawed, and you actually noticed it in your last paragraph. > >It's true that pondering is some compensation for being manual, but your game is >as good as your weakest move. It won't help you to ponder on a move for 10 >seconds if next move you guessed wrong and have to make a move in one second. > >Another obvious point is that games often last more than 60 moves, especially >against an opponent who never takes a draw and often plays to mate. There's >definite risk of losing on time, and my record against crafty has several losses >on time in a won or drawn position. > >I don't make excuses for Junior. It was my decision to play this way, but, since >you are carefully analyzing the true odds here, take all factors into account >and make it realistic. > >Taking all into account, and correcting crafty's speed to 4x400, I think my >original formula is sound and computes to about 1:4.5 CPU ratio. > >Amir All I can say is that 4X400 = 4.5*(2X350) is _truly_ remarkable mathematics, and I was a math major. I am afraid that had I told any math instructor I had that 1600 == 4.5*700 I would have had to find another major. And I suspect that when you play crafty, your machine is _only_ playing crafty. Mine might or might not be just playing chess. I can get hurt seriously by other things, because crafty runs as a nice 20 process. Late at night, it is doubtful it is doing anything else. From 8am-8am, it is guaranteed to be doing something else a lot of the time, like compiling, testing, generating postscript documents, running nfs performance tests, etc... I don't complain, I just let it go... because that is "crafty"...
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