Author: Vincent Diepeveen
Date: 12:09:19 03/30/03
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Bob of course didn't proof anything as usual and all significant counts are not shown. To start with also the solutions of positions at BT2630 are found within a second or so, so are no good positions to use for such hashtable tests. I need to note however that where when DIEP runs single cpu my results are very similar to what you presented here, when you are parallel, things change a lot. For programs that search in parallel it is very important to have a big hashtable. I see clear differences there in speedup when using big hashtable versus small hashtable. That difference is likely to explain the assumption from Bob versus your 'proof'. Trivially the testpositions you used are better than the first 6 positions shown below: C:\engine\fen>type bt2630.fen rq2r1k1/5pp1/p7/4bNP1/1p2P2P/5Q2/PP4K1/5R1R/w f5g7 6k1/2b2p1p/ppP3p1/4p3/PP1B4/5PP1/7P/7K/w d4b6 5r1k/p1q2pp1/1pb4p/n3R1NQ/7P/3B1P2/2P3P1/7K/w e5e6 5r1k/1P4pp/3P1p2/4p3/1P5P/3q2P1/Q2b2K1/B3R3/w a2f7 3B4/8/2B5/1K6/8/8/3p4/3k4/w b5a6 1k1r4/1pp4p/2n5/P6R/2R1p1r1/2P2p2/1PP2B1P/4K3/b e4e3 Note that i am always amazed at how Bob picks his testpositions. Best regards, Vincent On March 30, 2003 at 14:09:33, Tom Kerrigan wrote: >On March 30, 2003 at 10:50:44, Robert Hyatt wrote: > >>Now I hope you will choose to dump that "this disproves the hyatt claim" >>stuff, you clearly didn't disprove _anything_... > >I was of course referring to: > >"The simple rule is that the hash table needs to be at _least_ large enough to >hold the entire tree." > >Don't you think the word "need" is a little strong in this situation? I mean, >chess programs work fine without huge hash tables, so maybe they don't "need" >them. > >I notice that you didn't present any data on how much of the search tree was >being stored in the hash tables, and without that data you obviously can't point >to a significant performance increase when the entire table is stored, so I >don't see that you even touched on the issue, much less proved it or disproved >it. > >-Tom
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