Author: Ed Schröder
Date: 15:08:39 02/01/02
Go up one level in this thread
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? Ed >-Andrew-
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