Author: Robert Hyatt
Date: 08:08:27 06/13/99
Go up one level in this thread
On June 13, 1999 at 10:02:45, Michel Langeveld wrote: >64bit has less positions with the same hashvalues than 32bit. I noticed almost >all hashvalues of positions are unique with 31-bit hashing. So will 32bit >enough? > >Michel Langeveld No. You can run the test yourself, like this: you need a machine with a lot of memory. Add an element to your hash table that is the _true_ position. I used 32 bytes when I did this, 4 bits per square. Store this for each hash position you store in the table. When you do a probe and get a match on the 32 bit signature, compare the 32 byte true position. You will get an _alarming_ number of misses on the 32 byte field when you just hit on the 32 bit field. With 64 bits I ran for hours with no false matches. With 32 bits, I got many per minute of searching..
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.