HyperThreading makes worse to me

[Maho NAKATA]

From: Ian Smith <smithi at nimnet.asn.au>
Subject: Re: HyperThreading makes worse to me (was Re: How to reproduce: Re: Only 70% of theoretical peak performance on FreeBSD 8/amd64, Corei7 920)
Date: Thu, 15 Apr 2010 14:21:30 +1000 (EST)

> Er, shouldn't one of those say HTT on?  and/or Turbo boost on?  Else 
> they're both the same test as [4] but with different results?
sorry,

Turbo Boost off, Hyper threading off: 82% (35GFlops)    [1]
Turbo Boost off, Hyper threading on: 72% (30.5GFlops)  [2]

HTT on performs always worse.

> Clarification of all four possible test configs - 8 if you add pinning 
> CPUs or not - might make this a bit clearer?
right. Pinning might not be so important I guess. Core i7 is not NUMA.

Thanks,
-- Nakata Maho http://accc.riken.jp/maho/ , JA OOO http://ja.openoffice.org/
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