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Subject: Re: WCCC: Almost no hardwareadvantage for Crafty

Author: Anthony Cozzie

Date: 06:13:34 06/30/04

Go up one level in this thread


On June 29, 2004 at 18:11:21, Robert Hyatt wrote:

>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.
>
>2x bigger doesn't mean much when comparing bitboard to non-bitboard.
>
>Not that I believe any of that anyway.
>
>At the moment, recent benchmarks suggest Crafty is significantly faster than
>Fritz on equal hardware which suggests that he is doing something different than
>in the past, as 3 years ago he was 2x-3x faster than me in raw NPS.
>
>But it doesn't matter.  We play what we have, and see what happens...
>
>
>>
>>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.
>
>That is dead on my quad 2.4ghz opteron speed.  I bet fritz is closer to 6M based
>on recent speed reports here...

From http://www.beepworld.de/members39/computerschach2/chessmarks.htm:

Athlon64 2.2 3400 1405 kn/s    Gian-Carlo Pascutto
Ahtlon64 3000+    1195 KN/s    Joachim Rang (2 Ghz, 512 Kb Cache)

This means that 1 processor 32-bit Fritz should get about 1250 KN/s.  Assuming
perfect nps scaling gives 5M nps.  However, I'm sure Frans has been busy
rewriting to AMD64 assembly; the big question is how much that gives him.

anthony



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