What should be minimum size of the Hash?

[ChessKnight]

I use WB + polygot with 3-4-5 men (Nalimov) and Scorpio bitbase.
What could be minimum size of the hash will serve purpose of proper probing?
Suppose hash size is large or too large (>128 Mb, or >256Mb) has any impact on chess engine performance?

reg
CK

[Dann Corbit]

I use WB + polygot with 3-4-5 men (Nalimov) and Scorpio bitbase.
What could be minimum size of the hash will serve purpose of proper probing?
Suppose hash size is large or too large (>128 Mb, or >256Mb) has any impact on chess engine performance?

reg
CK

Are you looking for minimums and maximums or optimal sizes?

For instance, if you are doing EPD analysis and giving one second per problem, then allocation of a 1 GB hash table will make the analysis much slower and inferior to a smaller hash table. But it will not cause incorrect results.

On Windows 32 bit operating systems, 2 GB is the max possible hash table size, but under 64 bit OS you can make it as large as you like.

The optimal hash size will be a function of many paramters (including your hash aging algorithms, whether you have secondary entries, and most of all the time control given for analysis).

As a general rule of thumb, the slower the analysis time, the larger the hash table should be. Very fast blitz and lightning games should use small hash and correspondence games or multiple hour EPD analysis should use the largest possible hash.

[ChessKnight]

Dann Corbit:

Thanks for informative reply.

Are you looking for minimums and maximums or optimal sizes?

- You answered the both nicely.

As a general rule of thumb, the slower the analysis time, the larger the hash table should be. Very fast blitz and lightning games should use small hash and correspondence games or multiple hour EPD analysis should use the largest possible hash.

-It makes sense to me.

reg
CK