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Subject: Re: Dual Xeon 2.8 GHz, Crafty 19.09 bench, cann't understand it (part 1) ...

Author: Frank Quisinsky

Date: 14:13:04 01/14/04

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On January 14, 2004 at 17:00:51, Gian-Carlo Pascutto wrote:

>The problem you are seeing is because any Windows versions prior to
>Windows 2003 Server do not understand hyperthreading correctly (even the
>claimed 'hyperthreading aware' Windows XP!).
>
>As a result, when you set MT=2, the two processes get randomly
>scheduled between the 4 processors, including the case where
>both processes are running on the same physical CPU.
>
>Use MT=4 or disable Hyperthreading, or upgrade OS.
>
>--
>GCP

Hi Gian-Carlo,

thanks for your information!
I will try it tomorrow with newer Xeons 3.2 L3 and Windows 2003 Server!

Shortly:
If I read your answer ...
That's means that I can set on Dual Xeon for SMP Eng - SMP Eng with ponder
_not_ MT=2 ?!

Right is (if I understand):
SMP Eng - SMP Eng with ponder ... I have to set MT=1 and I have to set
Hyper-Threading under Windows XP SP1 = off ?!

Under Windows 2003 Server:
SMP Eng - SMP Eng with ponder ... I have to set MT=2 and I can set
Hyper-Threading = on !?

... MT setting in the case of Crafty!

I will try it in the night with your engine too!

Best
Frank



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