Author: Frank Schneider
Date: 09:52:29 08/31/01
Go up one level in this thread
On August 30, 2001 at 13:23:15, Robert Hyatt wrote: >On August 30, 2001 at 12:37:34, Frank Schneider wrote: > >>On August 30, 2001 at 09:59:57, Robert Hyatt wrote: >> >>>On August 30, 2001 at 05:58:01, Dan Andersson wrote: >>> >>>>One really simple parallel search algorithm is to have two searches working >>>>independently. Only one search communicate with the output. But both share the >>>>same hash table and thus work together. If you are lucky, that can result in a >>>>good speedup. To increase the efficience of this algorithm, use ETC to get >>>>better use of the hash table, this won't strain bandwidth in the bulk of the >>>>search. >>>> >>>>MvH Dan Andersson >>> >>> >>>I don't see how this will perform reasonably when it is probable that both >>>processors will search the same tree at the same time, >> >>The idea is to detect all-nodes and let n-1 processors search the moves >>in a different (e.g. random) order. >> >>However, didn't work too well for Gromit so far :-( >> >>Frank >> > >My off-the-cuff analysis says that as you use more processors, this is going >to work worse and worse. I agree and probably Rudolf (Rudolf Huber, Parsos) has tried it and can confirm it. > >A normal tree-splitting search seems to me to be the right way to do this. Yes, I'm afraid... >Although I realize it is a lot of work with some complex data structures >and timing issues. The "easy way out" is generally not very good overall. Frank > > > >>> and hashing won't stop >>>that from happening. This might be better than nothing. As might the ABBADA >>>idea, but good old intentionally deliberate parallel searching has to be >>>better than these "uncoordinated approaches". >>> >>>The shared hash table with the "exclusive bit" is a big problem on most >>>machines. Locking hash entries is a performance killer, and they have to be >>>locked if such a bit is used.
This page took 0 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.