Author: Tony Werten
Date: 01:54:11 04/15/03
Go up one level in this thread
On April 14, 2003 at 17:43:12, Robert Hyatt wrote: >On April 14, 2003 at 17:15:41, Vincent Diepeveen wrote: > >>On April 13, 2003 at 22:39:39, Robert Hyatt wrote: >> >>>On April 13, 2003 at 11:49:28, Vincent Diepeveen wrote: >>> >>>>On April 13, 2003 at 11:27:53, Robert Hyatt wrote: >>>> >>>>I said initially. It drops back to 10 splits a second in DIEP after a while. >>>>Search depth matters. >>>> >>>>Let's compare 2 things. >>>> >>>> time=45.98 cpu=464% mat=0 n=37870294 fh=88% nps=823k >>>> ext-> chk=638414 cap=249442 pp=9588 1rep=32966 mate=223 >>>> predicted=0 nodes=37870294 evals=14565859 >>>> endgame tablebase-> probes done=0 successful=0 >>>> hashing-> trans/ref=28% pawn=93% used=28% >>>> SMP-> split=431 stop=57 data=6/64 cpu=3:33 elap=45.98 >>>> >>>>MT 2 crafty 18.10 which i have here. 431 splits at 45 seconds. I guess you must >>>>limit in crafty the number of splits a lot as splitting is expensive in crafty >>>>when compared to the costs of a single node. >>> >>>I'm not sure how expensive it is compared to a node. I'll run a test where >>>I do the split overhead at every node to compare, however... >>> >>> >>> >>>I don't limit them at all. The only limit is the YBW algorithm. But I split >>>at the root also, which reduces them signficantly... >> >>I can split at the root nowadays, but i have turned it off for diep. it gives >>too poor speedup for me. The interesting thing which searching SMP can give is >>transpositions at a big depth which possibly are overwritten by a sequential >>search. i don't want to miss them. > >Maybe you don't split at the root correctly. I limit this with some intelligent >guesswork, so that if it appears that I might change my mind this iteration, >then >I don't split at the root until I have searched all moves that I think might >replace >the best move... Just trying to understand. Are you talking about the case where the best move in the root got a fail low ? When that happens, your testresults indicate that's it's better to split lower than to search 2 rootmoves parallel in order to get an established score asap ? ( So not breaking off seacrh when 1 gets a first failhigh, but only when the score is resolved ) Tony > > >>
This page took 0.01 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.