linux-kernel - Re: How to detect multi-core and/or HT-enabled CPUs in 2.4.x and 2.6.x kernels

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Message-Id: <1167233935.3281.3955.camel@laptopd505.fenrus.org>
Date:	Wed, 27 Dec 2006 16:38:55 +0100
From:	Arjan van de Ven <arjan@...radead.org>
To:	Gleb Natapov <glebn@...taire.com>
Cc:	knobi@...bisoft.de, linux-kernel@...r.kernel.org
Subject: Re: How to detect multi-core and/or HT-enabled CPUs in 2.4.x and
	2.6.x kernels


> If I run two threads that are doing only calculations and very little or no
> IO at all on the same socket will modern HT and dual core be the same
> (or close) performance wise?

it depends on how cache/memory bandwidth sensitive your calculation
is.... if your calculation is memory bandwidth sensitive then they're
the same. If your calculation is very sensitive to have the dataset fit
in cache.. it's another different ballgame again, because then it
depends if the cores in your dual core share the cache or not.


-- 
if you want to mail me at work (you don't), use arjan (at) linux.intel.com
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