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Subject: Fritz 7: Hashtable size versus Fritzmark

Author: karen Dall Lynn

Date: 08:24:14 03/09/02


Greetings [[all]]

Steve Lopez has recently released a T-note advancing a formula to deploy
optimized hash table sizes. As known, the formula is a function of processor
size and average thinking time per move. What is characteristic of this formula
is that it settles much smaller hashtable sizes than I have been using or than
the most commonly referred sizes in ordinary games.

But if hashtables should be set to something between 16-64Mb for ordinary blitz
games on processors 1500(+-)500 Ghz, **why the call of the optimize-strength
funcion in Fritz 7 makes the hashtable size grow to the top size under available
RAM?*** In my case, it increases to 608Mb from my 768Mb, leaving sometimes no
more than 7-30Mb to the rest? Again, if Steve Lopez' formula is the right way to
do it, why Fritz 7 optimizes strength entering bulk sizes to fat hashtables? Why
the program does not apply some algorithm akin to the thinner proposed formula?

I have also tested my F7 Fritzmark (P4 1500Ghz/768Rambus)against distinct
hashtable sizes, getting the following results:

16Mb  763kN/s (+-)7
32Mb  785kN/s (+-)14
64Mb  801kN/s (+-)0
128Mb 778kN/s (+-)0
256Mb 763kN/s (+-)5
512Mb 723kN/s (+-)18

It suggests that neither top nor bottom sizes will mirror optimal hardware speed
- so, if hardware speed is a hallmark of efficience, maybe optimizing
automatically strength will boil down to a slower and therefore less efficient
engine ability.


Karen




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