Author: Andrew Dados
Date: 15:34:52 02/01/02
Go up one level in this thread
On February 01, 2002 at 18:08:39, Ed Schröder wrote: >On February 01, 2002 at 15:10:14, Andrew Dados wrote: > >>On February 01, 2002 at 00:28:08, Robert Hyatt wrote: >> >>>On January 31, 2002 at 14:04:13, Andrew Dados wrote: >>> >>>> >>>> >>>>From their own publication, 'Deep Blue', June 2001 >>>>Example of search depths over one position >>>>r1r1q1k1/6p1/3b1p1p/1p1PpP2/1Pp5/2P4P/R1B2QP1/R5K1 w >>>>from DB-Kasparow game 2 from 1997, before move 37 >>>> >>>>When chips were set to minimum fullwith 4 plys: >>>> >>>>A.Iteration >>>>B.Minimum software depth >>>>C.Maximum software depth >>>>D.Maximum Estimated combined depth >>>> >>>>A B C D >>>>---------------- >>>>6 2 5 11-21 >>>>7 3 6 12-22 >>>>8 4 11 17-27 >>>>9 5 15 21-31 >>>>10 6 17 23-33 >>>>11 7 20 26-36 >>>>12 8 23 29-39 >>>> >>>>So iteration is clearly the sum of minimum software depth (B) and hardware depth >>>>(4 plys here). >>>> >>>>-Andrew- >>> >>> >>> >>>OK... but what does this have to do with the current discussion? DB doesn't >>>report "an iteration number". It reports things like 10(6) and directly >>>according to Hsu (from the email I posted) 10 is the software depth, and (6) >>>is the hardware depth. They are _added_ to get the total depth... >> >>Why would they publish a table to depth 12 if they searched till d=18 in real >>game? >> >>Recap: >> >>Arguments for depths of 17-18: >> >>1) Your email from Hsu >>2) DB logs, which show something, like 8(4) line followed by 8(6) line. >> >>Arguments against reaching d=18: >>1) Quotes by David Fotland from Dr Campbell on RGCC as I reposted here. >> >>2) According to their publication avg search speed over DB-Kasparov match was >>126M nps. As you and Ed noted ebf of DB is 4. No matter how they prune, those 2 >>numbers stand. >> >>Then time to finish depth 18 would be x*4^17/126Mnps, where x depends on search >>model, qsearch, extensions, SE etc. That x can not be less then 30 (no qsearch), >>more like 1000 for their search model. 4^17/126Mnps = 136 sec. >>for x=30 we get 68 minutes to finish depth 18; for x=1000 we'll get 2266 >>minutes. In the match DB searched for about 3 minutes/move. >> >>3) When DB sees some tactics in 10(6) line, is was noted that current PC >>programs see that in depths 10-12 (current programs heavily prune and extend way >>less comparing to DB). > > >>No matter what is true, you have to agree some things are not consistent here. > >Right. > >Now let's have a look at things from Bob's point of view and assume the >information is correct. Most of the time the logs shows 10(6) and 11(6). Can the >host (the IBM RS/6000 SP from 1997) do a 10-11 ply brute force search with all >those heavy extensions? If so, it then will all depend how fast the chess chips >are doing their 6 ply searches. Each chip is claimed to do 2-2½M NPS. I can not >find an average time for doing a typical 6 ply search in the hardware but if is >an accepatable time it is maybe doable? As I recall chips were set to abort the search after 8000 nodes and report back to host for possible split. So timeout would occur in 1/250 sec. I have no info on average chip nodecounts, though. > >Ed > > >>-Andrew-
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