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Subject: Re: IBM's latest monster

Author: Robert Hyatt

Date: 12:33:03 12/06/99

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On December 06, 1999 at 13:00:56, Georg v. Zimmermann wrote:

>>A thousand fold increase would be
>>what, an additional 6 ply search in the same time?
>
>Lets do some math. 40^x = 1000,  40log 1000 = x, x = 10log1000 / 10log40, x =
>3/10log40 = 3 / 1.5 = 1.9
>
>I think it gets you "1.9 ply" deeper if you do brute force. Now we need someone
>to tell us how much that is if you add HT and other modern wunder drugs.
>But I would be very very suprised if you'd reach +6ply.


DB has an effective branching factor of roughly 6, about the same as Cray
Blitz, which didn't use R=2/recursive null move.  Log6(1000) is at most 4,
so it would get about 4 plies deeper.  Certainly nothing to sneeze at...

But then again, this math is really wrong, because for each cpu, DB used
16 chess processors.  Each chess processor could search about 2.4M nodes per
second (they used almost 500 for DB2 the last match).  With one million
processors, they would then have 16M chess processors, and would be
searching about 40,000,000,000,000 nodes per second.  At about 1 billion
(max) for DB2, this would be 40,000 times faster.  and log6(40000) is 6,
so they could hit about 6 plies deeper.  Very dangerous box...



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