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Subject: Re: Q&A with Feng-Hsiung Hsu

Author: Vincent Diepeveen

Date: 02:12:59 10/14/02

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On October 14, 2002 at 02:43:37, Slater Wold wrote:

>On October 13, 2002 at 23:10:38, Keith Evans wrote:
>
>>On October 13, 2002 at 14:25:00, Vincent Diepeveen wrote:
>>
>>
>>>You cannot use killermoves in hardware and you cannot use hashtables
>
>You sure the hell can.

in theory you can, but the slowdown is too big.

IBM asks for the maximum nodes a second. CPUs are clocked 20 or 24 Mhz.
the 20Mhz is easier to calculate with.

It gets about 2 million nodes at 1 cpu.

That's 10 clocks. 20Mhz / 10 clocks = 2 million nodes a second.

If you add killermoves, then in move ordering phase it will require 2
extra clocks to use them, i assume storing them goes in parallel again.

that's 20Mhz / 12 clocks = 1.7 MLN nodes a second.

If you add hashtables that'll eat like 4 clocks in the sequential search.

So then you drop to 20 / 16 = 1.25MLN nodes a second.

Now i would still go for it, if it just eated 4 clocks and 2 clocks for
killermoves. Killermoves give more like 20% speedup.

However things get more complicated than this when the searches were
very small in the hardware, and according to hsu's statements so far it
seem they were.

>>I don't see any technical reason why this would be true. It shouldn't be a
>>problem to hack killermoves into a Belle style move generator  - see what Marc
>>Boule did in his master's thesis.
>>
>>Even Hsu mentions that hashtables are possible. (Not in the latest chat - just
>>see his previous publications.)
>>
>>Keith



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