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Subject: Re: Is improvement from hash tables in middle game linear or exponential?

Author: Thomas Mayer

Date: 05:43:37 12/20/03

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Hi Vincent,

>I did 2 experiments:
>
>experiment A) I ran diep at 460 processors with 115MB hashtable *in total*
>experiment B) Same diep version at 460 processors with 115GB hashtables.
>
>Note hashtable means transpositiontable here. Each processor had local 4.2MB
>pawnhashtable and each processor had local 32MB evaluation table.
>
>MB = 10^6 , GB = 10^9
>#probes   = 4
>entrysize = 16 bytes
>position  = r4rk1/p1q1nppp/b2b4/2nP4/1P3p2/P1N2N2/B1P3PP/R1BQK2R w KQ -
>
>What is the expected outcome?

well, there are several unclear facts - e.g. how to usage of 460 processors is
different to the usage of 1 processor etc.

Anyway, let's try a guess and take the idea of Christoph Theron that hashtable
doubling is about 7 Elo... We have 10 doublings, so 70 Elos expected... Doubling
in speed is expected with around 60 Elos... So I expect a speedup of about
120-150%... How far am I away ?! :)

Greets, Thomas



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