Author: Robert Hyatt
Date: 21:41:13 07/21/00
Go up one level in this thread
On July 22, 2000 at 00:24:39, blass uri wrote: >On July 22, 2000 at 00:07:18, Robert Hyatt wrote: > >>On July 21, 2000 at 23:36:51, blass uri wrote: >> >>>On July 21, 2000 at 23:27:47, Robert Hyatt wrote: >>> >>><snipped> >>>>Here is my numbers, on a quad xeon/550mhz machine. >>>> >>>>9 plies took 2M nodes >>>>10 plies took 5M nodes (this is 5M total from plies 1-10) >>>>11 plies took 9M nodes >>>>12 plies took 100M nodes >>>>13 plies took 500M nodes >>>>14 plies took 700M nodes >>>>15 plies took 1300M nodes >>>> >>>>If I could average 200M nodes per second, I could do that search in probably >>>>under 5 seconds, given enough memory. If I could peak at 1B, I could do that >>>>search between 1 and 5 seconds somewhere, depending on how the peak went... >>>> >>>>Note that his 30% efficiency figure is an average as is my 3.2X faster on a >>>>quad. I have many positions where I run 4x faster. I have a couple where >>>>I run 1/10th as fast as one cpu... >>>> >>>>For me, these numbers should be reduced by at least 25%, which is my search >>>>overhead (extra nodes searched that a sequential search would not examine). >>>>Hsu's 200M figure already had his overhead factored out... >>>> >>>>I am not sure what this proves, when you factor in parallel search. Odd >>>>things happen. Some searches go way fast. Others go way slow. Trying to >>>>compare searches by comparing depths is not so useful. In some positions >>>>I might extend way too much. In other positions they might do the same. >>>>In other positions we might extend pretty equally. How to know and compare? >>>> >>>>I could probably search this tree in less than 1/2 the nodes if I had a decent >>>>sized hash table. This grossly overruns anything I can use on this machine >>>>tonight... >>> >>>Did you use recursive null move pruning in this search?(I think you should not >>>use null move pruning in order to do the right comparison) >>> >>>Uri >> >> >>I ran "crafty". I can turn null off. or anything else. But it still doesn't >>give us an accurate comparison. Remember that DB has two parts to the search. >> >>The first number is the software search, which does _all_ their extension stuff >>including singular extensions and whatever. The second number is their hardware >>search which doesn't do singular extensions. I am pretty sure the hardware does >>"out of check" extensions as Belle did and the hardware was patterned after the >>Belle machine. Belle didn't do recapture extensions, so I don't know whether >>the DB chip does or not. The DB hardware does do futility pruning in the q- >>search while not everybody does that (I do). So comparing their 9+6 time to >>my 15 time is probably not right. There 9+6 is probably closer to my 13/14 >>when you factor in the fact that I can trigger extensions anywhere from ply 1 >>to ply N, while for them, the last 6 plies trigger fewer extensions in the >>hardware. > >I understood that you claim that they do more extensions than other programs and >not less extensions(if they cannot trigger extensions in the last 6 plies >then the picture may be different and I may be right that they played c4 against >Fritz3 because of lack of extensions). > >Uri Note that I didn't say "no extensions" in the last 6 plies. I said "no singular extensions in the last 6 plies". I really don't remember exactly what extensions they did although I will try to find out. I know that Belle did the classic "out of check extension" and that the DB chip was really belle on a single chip, with a much-needed design enhancement to eliminate a stack that belle needed. And knowing that, I am pretty sure they did the check extension, and possibly others. The chip was designed in 1987, so they likely did whatever was "current" at that point in time, at least. Plus the other extensions they did in the first N plies in software... I have been trying to find my notes on the old *socrates game, as it was a pretty good Deep Thought tactical crush. *Socrates didn't see the roof falling until it was way too late, yet their reported nominal search depth was greater than that of deep thought (they were actually on faster hardware, a big CM-5 somewhere). Mike Valvo gave a detailed lecture on the game during the next evening's games, as he was so impressed with their play there and the tactical things they were seeing. I will see if I can find the game, and we can look at the moves... I think it was the last ACM in Cape May...
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