Manual de Houdini 3 2012 | Page 241

Reference

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For infinite analysis or long time control matches you should use the largest hash that
fits in the physical memory of your system. For example, on a system with 4 GB of
memory you can use up to 2048 MB hash size.
For shorter games, for example 3 to 5 minute games, it’s better to use 256 MB or 512
MB as this will provide the best performance. For 16 min games 1024 or 2048 MB hash
size should be fine.
Never Clear Hash (checkbox): This option prevents the Hash Memory from being
cleared between successive games or positions belonging to different games.
Check this option also if you want to Load the Hash from disk file, otherwise your
loaded Hash could be cleared by a subsequent ucinewgame or Clear Hash command.
Persistent Hash means that the in-memory hash table can be saved to a disk file and
reloaded later for continuing the analysis.
The goal is to be able to interrupt a long position analysis anytime and save the hash
table to a disk file. At a later date you can reload the hash file in memory and continue
the analysis at the point where it was interrupted.
Correspondence chess players could profit from this feature by keeping one hash disk
file per ongoing chess game. For that purpose the following procedure can be used.
To save a Hash file to disk:
· End the analysis
· Go to the options window, enter the name of the Hash File (e.g. C:\Chess\Game1.
dat)
· Press the Save Hash to File button, and OK in the options window.
To load a Hash file from disk:
· Load the correspondence game
· Go to the options window, enter the name of the Hash File (e.g. C:\Chess\Game1.
dat)
· Press the Load Hash from File button, and OK in the options window.
Hash File
File name for saving or loading the hash file with the Save Hash to File or Load Hash
from File buttons.
A full file name is required, for example C:\Chess\Hash001.dat.
By default Houdini will use the hash.dat file in the "My Documents" folder of the
current user.
Save Hash to File (button)
Save the current hash table to a disk file specified by the Hash File option.
Use the Save Hash to File button after ending the analysis of the position. Some GUIs

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