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Subject: Re: Some Crafty 16.19 results on my XP 2.44GHz

Author: Robert Hyatt

Date: 08:40:27 02/19/03

Go up one level in this thread


On February 19, 2003 at 00:52:09, enrico carrisco wrote:

>On February 19, 2003 at 00:19:41, Robert Hyatt wrote:
>
>>On February 19, 2003 at 00:11:08, Aaron Gordon wrote:
>>
>>>I just downloaded Crafty 16.19 and ran a bench for you guys. No single cpu Intel
>>>box could ever touch this without sub-zero cooling. Just plain not going to
>>>happen.
>>>
>>>Crafty v16.19
>>>
>>>White(1): bench
>>>Running benchmark. . .
>>>......
>>>Total nodes: 67136136
>>>Raw nodes per second: 1766740
>>>Total elapsed time: 38
>>>SMP time-to-ply measurement: 16.842105
>>
>>
>>This is not a great test since that is a very old version.  I'm not sure how
>>1.7M compares to version 19.3 in nps...
>>
>>However, while on the question, what is an XP 2.44ghz machine, since I am not
>>an AMD expert.  Overclocked?  If so, I consider that a worthless number, because
>>of obvious reasons...
>
>
>If done properly and tested for reliability -- what reasons do you speak of?
>Most CPUs are purposely locked from higher than marked performance from the
>manufacturer for marketing and other reasons -- both Intel and AMD.  This, in no
>way, means the CPU is incapable of such performance.

The reason is _reliability_.  As I explained in another post, circuits have a
distinct settling
time, which is what limits the clock frequency.  Some circuits have varying
settling times
depending on the inputs.  If you set the clock frequency too short, on occasion
the circuit
won't settle before the outputs are latched, and you get flakey results.  Unless
you do a
complete and exhaustive test of all instructions, all inputs, you can't be sure
you haven't
stepped on this.  I have debugged this problem in the past and don't _ever_
intend to debug
it again.






>
>In the case of AMD, chips with the same stepping are identical no matter what
>they're marked. So if a 1500+ AthlonXP has an AIUHB 0301 core and an AthlonXP
>2800+ has an AIUHB 0301 then they'll be able to run identical speeds.
>(Obviously there are slight variations in peak performance, if you're going for
>higher than XP3000+ level.)
>
>Are you suggesting that "unlocking" performance that is already included in the
>core simply because the marking on the top of the cpu says otherwise makes such
>results worthless?
>
>Wouldn't that be the same as saying stronger results I may find with Crafty if I
>modified the settings are completely worthless if you did not include the
>settings in your official release?
>
>-elc.
>
>P.S. ICGA doesn't have any regulations on the overclocking of any CPU(s). :)



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