Author: Robert Hyatt
Date: 06:46:47 01/08/01
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On January 08, 2001 at 04:07:56, Jouni Uski wrote: >1. I see in Crafty source code, that it has 16 bytes hash key. So 100MB hash >table contains 6 250 000 entries. If Crafty's node speed is 200K this means, >that hash table is enough for only 30s of counting. Correct? Probably not. >But how can we aproximate time for this 100MB hash to fill? First, remember that I don't hash in the q-search. So at _least_ 1/2 of the total nodes searched never make it to HashStore() at all. That makes a big difference. Second, 100mb is impossible for Crafty. 96mb will work, but the rule is that my hash size must be 3/4 of a perfect power of 2. > >2. When we have 6 250 000 entries in hash, isn't it taking very long time to >find if position is there?! No. That is what "hashing" is about. Convert the 8-byte hash signature into a single memory address and look there. If it isn't there, it isn't anywhere. No sequential searching thru that table, or else it wouldn't work at all. > >thanks Jouni
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