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Subject: Re: WCCC: Almost no hardwareadvantage for Crafty

Author: Robert Hyatt

Date: 09:48:06 06/29/04

Go up one level in this thread


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...

Time will tell...





>
>>Fritz does not use bitboards by the way...



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