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Re: The new scheduler and x86 CPUs


Vladimir Makarov wrote:

> As for the data, I see the following

> http://www.spec.org/osg/cpu2000/results/res2001q2/cpu2000-20010604-00681.html

> Alpha 833Mhz: base : 643

> http://www.spec.org/osg/cpu2000/results/res2001q2/cpu2000-20010522-00660.html

> Itanium 800 Mhz: base: 701

> If 342 for Itanium were for gcc, I would not be surprised.

<Shrug>  Look again.  The 342 for Itanium vs. 544 for Alpha is for the
_apsi_ program.

This makes it (again) clear why it is so dangerous to *only* look at the
bulk number for SPEC, something that SPEC keeps pointing out.

The reason why it is interesting to look at a weather forecasting
program (actually, apsi is a dispersion model based on a weather
forecasting model) is that these programs tend to *not* have a single
hotspot that you can easily design your compiler for.

Of course, this doesn't rule out that OOO implementations wouldn't run
out of steam eventually against newer paradigms, but the Itanium is
definitely not proof of that.

--
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Tel. +31302206443, Fax +31302210407,  e-mail moene@knmi.nl
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