From: Scott Robert Ladd <coyote@coyotegulch.com>
To: "J.A. Magallon" <jamagallon@able.es>
Cc: Artemio <artemio@artemio.net>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: SMP question
Date: Thu, 12 Jun 2003 10:02:34 -0400 [thread overview]
Message-ID: <3EE887FA.90008@coyotegulch.com> (raw)
In-Reply-To: <20030611225401.GE2712@werewolf.able.es>
J.A. Magallon wrote:
> In short, for FP intensive tasks, hyperthreading is a big lie...
> You can't run 2 computations in parallel.
Yes and no; the benefit of HT depends on the application in question.
I've seen everything from a 5% LOSS in performance to a 30% INCREASE in
performance, for intensive floating-point code. This is with programs
parallelized with OpenMP and Intel's C and Fortran compilers. I'm still
analyzing the exact nature of the benefits, but they *do* exist.
While I much prefer multiple physical CPUs to "virtual" CPUs, HT *does*
provide performance improvements for certain applications. To call HT a
"big lie" is both provacative and inaccurate.
--
Scott Robert Ladd
Coyote Gulch Productions (http://www.coyotegulch.com)
next prev parent reply other threads:[~2003-06-12 13:50 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-06-11 17:43 SMP question Artemio
2003-06-11 18:04 ` Tigran Aivazian
2003-06-11 19:38 ` Samuel Flory
2003-06-11 19:52 ` Artemio
2003-06-11 20:14 ` David Schwartz
2003-06-11 20:13 ` Artemio
2003-06-11 22:34 ` David Schwartz
2003-06-11 22:54 ` J.A. Magallon
2003-06-12 5:37 ` Artemio
2003-06-12 12:49 ` Matt Reppert
2003-06-12 17:25 ` Artemio
2003-06-12 14:02 ` Scott Robert Ladd [this message]
2003-06-12 20:59 ` J.A. Magallon
2003-06-11 21:25 ` Zwane Mwaikambo
[not found] <Pine.LNX.4.44.0306111838360.20310-100000@coffee.psychology.mcmaster.ca>
2003-06-12 5:42 ` Artemio
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