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Subject: Re: Computer(CPU)benchmark for chessprograms

Author: Robert Hyatt

Date: 21:20:35 01/16/98

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On January 16, 1998 at 22:36:10, Detlef Pordzik wrote:

>This sounds remarkable to me, since I haven't such a good education of
>the
>" what's going on inside ".
>As far as I know, and from my own experience, progs like, for instance,
>G5
>don't care too much for big hash tables, whilst, for example, R9 fills
>up his
>maximum capacity of 60 megs quite fast - mostly.
>I once had a try with F5 - just to see, if it really was true, and
>allowed him 85 megs on my 128 MB system.....full within about 5 minutes
>- I simply can't believe, that this is efficient ?
>Now to my question :
>is there, using W 95, a kinda standard or approx formula, how much hash
>to allow the program working on unlimited analysis time, which means,
>for example, 8 hours ?
>Then, of course, stand alone. - Or is it so - as I would suggest, that
>it depends on the prog in the end....and in one's own experience ?

First, let's dispell a myth:  full = bad.  Hashing is not going to quit
when the table fills.  Everyone uses reasonable replacement policies.
Don
Beal ran some tests and wrote a paper in an ICCA issue last year.  Until
you
get into the 10x area (you have searched 10X the number of nodes that
can
fit in your hash table) the search won't degrade a tremendous amount.
If
you have done your homework on the replacement policy, we are talking
about
percentage ranges in the 10% to 20% range, *after* you search 10X the
number
of nodes you can store in the hash...

This means that you can search until the table fills, and keep right on
going,
and not expect the roof to fall in.  *unless* Frans tried to make it so
fast
that he didn't take the time to develop a reasonable replacement
strategy,
something I find difficult to believe.

So full != bad.  2X full is worse than not full, but you might get the
impression this is a horrible slow-down.  It isn't...



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