Author: Angrim
Date: 07:15:16 08/29/01
Go up one level in this thread
On August 28, 2001 at 21:47:33, leonid wrote: >On August 28, 2001 at 16:21:30, Angrim wrote: > >>On August 28, 2001 at 05:39:13, leonid wrote: >> >>>[D]6kq/rqqrqqqq/n2Q4/b1PNRBBN/b2Q3N/p2Q3K/n2P2Q1/q1Q2RR1 w - - >>> >>>Please indicate your result. >>> >>>Thanks, >>>Leonid. >> >>Athlon 1.2ghz, pn^2 without pn-transpositions: >>proved that move f5xh7 wins, 11 turns >>PN2:1146353 evals, 31056 expands, 3.91 seconds >> >>Athlon 1.2ghz, pn^2 with pn-transpositions: >>proved that move f5xh7 wins, 11 turns >>PN2:952464 evals, 22224 expands, 3.36 seconds >> >>Athlon 1.2ghz, pn-search with transpositions: >>proved that move f5xh7 wins, 11 turns >>PN:261248 evals, 6348 expands, 24 max ply, 0.95 seconds > > >Hi, Angrim! > >What is finally your time for solving this position? It look like it is very >short but I am not certain what, between few figures that I see here, is final >number. The numbers shown are for three independant searches each useing a somewhat different method. The fastest time to solve it was 0.95 seconds. The reason that I do not use pn-search(rather than pn^2 search) for most of your puzzles is that pn-search is memory bound and so if it can not solve the problem before I run out of ram then I have to use pn^2 search which uses vastly less memory at the expense of some(usually 2-3x) speed. > >I tried to guess already few time if I have something in my solver like your >pn-search but never had clear response. > >My time was very bad on this position. It took 11 seconds (your look to be 3.36 >seconds) and selective find mate only in 10 moves. By brute force it took 12 min >and 55 sec to find shortest mate in 8 moves. Celeron 600Mhz. No hash. > >I don't think that hash give that much help on selective search since there are >only few nodes used on each ply. But hash should be very helpful on brute force. The importance of hash tables for selective search is transposition detection. > >Cheers, >Leonid. > > > >>pn-transpositions meaning that the search checks for transpositions in >>the secondary pn-search as well as in the primary pn2 search. I >>just recently implemented this for use in my suicide chess program, >>but it seems to also pay off for standard chess. This costs a bit >>of speed(nps) but seems to be well worth it. >> >>Also clearly raw pn-search is much(3x) better than pn^2 search, but >>only if you have enough ram(pn-search is best-first search so all nodes >>must be stored in ram) >> > > > > >>Angrim
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