Author: Robert Hyatt
Date: 07:37:17 05/09/02
Go up one level in this thread
On May 08, 2002 at 18:34:24, Brian Richardson wrote: >On May 07, 2002 at 22:36:40, Will Singleton wrote: > >>On May 07, 2002 at 22:04:05, Brian Richardson wrote: >> >>>On May 07, 2002 at 13:34:34, Robert Hyatt wrote: >>>>Nothing wrong with starting simple. Always store entries in the normal search, >>>>don't in the q-search. It will be easy to add it to the q-search later if you >>>>think you want to try it... >>>> >>>>A single always-replace table will not be anywhere near as good as the two-table >>>>approach most of us use (one is always replace, the other is replace with deeper >>>>draft only). >>> >>>I have tested this several times with Tinker. In nearly all cases a single >>>table (replacing when id is different, or based on depth when the same) does >>>better than the 2 table approach. Some of the tests in ICCA are based on much >>>older systems with smaller main memory sizes. I think with modern memory sizes >>>and hash tables much greater than 1 million entries, things change. Tinker >>>usually runs with 32M entries. >>> >>>In any case, you may want to try both 1 table and 2 in your program, since each >>>search is somewhat different. For example, hashing q-search entries is also >>>faster for Tinker, but apparently not for Crafty. >> >>Have you experimented with your single table approach on Fine70? Vs the dual >>table approach? On that position, and others, 2 tables seems better. >> >>Will > >Yes, either way works with Fine70...only the single hash table is about 5% >faster, at least for Tinker. >Brian The single table approach will cause some problems when things get "overloaded". Deep draft entries will monopolize the table space making local searches take much longer due to no hash space for the shallow-draft entries... If you use a big table and a shallow search, you can't tell the difference. It becomes visible with small tables and deep searches, or big tables and even deeper searches...
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