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Subject: Re: WCCC: Almost no hardwareadvantage for Crafty

Author: Djordje Vidanovic

Date: 01:21:14 06/30/04

Go up one level in this thread


On June 29, 2004 at 18:06:27, Vincent Diepeveen wrote:

>On June 29, 2004 at 17:57:07, Djordje Vidanovic wrote:
>
>>On June 29, 2004 at 15:50:00, Vincent Diepeveen wrote:
>>
>>>On June 29, 2004 at 12:48:06, Robert Hyatt wrote:
>>>
>>>>On June 29, 2004 at 12:28:03, Vincent Diepeveen wrote:
>>>>
>>>>>On June 29, 2004 at 11:56:05, Robert Hyatt wrote:
>>>>>
>>>>>>On June 29, 2004 at 11:25:08, Jaime Benito de Valle Ruiz wrote:
>>>>>>
>>>>>>>On June 29, 2004 at 08:26:15, Zach Wegner wrote:
>>>>>>>
>>>>>>>>One important point is that crafty uses bitboards, so it will have an additional
>>>>>>>>speedup on a 64 bit processor.
>>>>>>>
>>>>>>>I might be wrong, but I think that Fritz also uses bitboards (I don't know about
>>>>>>>Shredder).
>>>>>>>Anyway, what about the compiler? And what extra efficiency do you expect from a
>>>>>>>64-bit processor? Enough to outsearch all other engines running on similar
>>>>>>>processors?
>>>>>>>
>>>>>>>Jaime
>>>>>>
>>>>>>
>>>>>>AMD has tested Crafty to answer this question.  They compiled it for 32 bits,
>>>>>>and for 64 bits.  The 64 bit version runs 47% faster than the 32 bit version,
>>>>>>everything else remaining constant.
>>>>>
>>>>>Going from 32 to 64 bits also the number of registers moves up from 8 to 16
>>>>>which is a big speedup also for Crafty and is inside that 47%.
>>>>
>>>>
>>>>Does not change their statement or measurement...
>>>>
>>>>And the question will be whether or not the commercial guys use a beta compiler
>>>>to produce accesses to those extra registers.  If, as you always claim, fritz is
>>>>in ASM (rather than what Frans claims, that it was rewritten into pure C a
>>>>couple of years back) then it won't be able to touch those registers either...
>>>
>>>Fritz will be opteron assembly, read my lips...
>>>
>>>Please show me a statement from Frans where he quotes it is written entirely in
>>>C. I cannot remember that at all. They (reporters) just ask whether 'fritz' is
>>>written in C. The answer is probably 'yes' to that (interface).
>>>
>>>>Time will tell...
>>>>>>Fritz does not use bitboards by the way...
>>
>>
>>
>>Fritz will hit 25 million kn/s, reaching ply 17-18 in the middlegame... :-) And
>>it will be Opteron ASM, by the way :-)
>
>I'm not so sure about speed. Commercially they will say it's C++ when that is in
>their interest to say, they will say it's C when that's in their interest and it
>will be assembly when it is in their interest to say so.
>
>But the *engine* is in assembly, let's be clear there.
>
>I would expect about 15 million nps, except that last years Frans has put more
>knowledge into evaluation. I remember he said already around 1999 he had an
>evaluation exactly 2 times bigger than crafty, so i guess that'll be at least 4
>times bigger by now.
>
>That will slow it down.
>
>Also it's doing seemingly checks in qsearch which slows it down.
>
>I expect somewhere around 9-10 million nps or so. That's about 1000 cycles a
>node.


Well, I said that "Fritz will hit..." not "Fritz will be hitting...", meaning
that it _will_ occasionally hit 25 mil kn/s, even in the middlegame.   Generally
speaking, I'd go along with the 10 mil nodes per second estimate, and, of
course, I agree that it will run in ASM.  The knowledge will slow it down a
little, but not much.  Frans Morsch has always been known for _maximal_
optimisation and efficiency.




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