Date: Thu, 7 May 2009 06:57:44 -0700 (PDT) From: Barney Cordoba <barney_cordoba@yahoo.com> To: pluknet <pluknet@gmail.com> Cc: "Current@freebsd.org" <Current@freebsd.org> Subject: Re: Hypertherading Message-ID: <418018.46727.qm@web63901.mail.re1.yahoo.com> In-Reply-To: <a31046fc0905061955u4a7b5755ifbcd7bd5641cd954@mail.gmail.com>
next in thread | previous in thread | raw e-mail | index | archive | help
--- On Wed, 5/6/09, pluknet <pluknet@gmail.com> wrote: > From: pluknet <pluknet@gmail.com> > Subject: Re: Hypertherading > To: "Barney Cordoba" <barney_cordoba@yahoo.com> > Cc: "Current@freebsd.org" <Current@freebsd.org> > Date: Wednesday, May 6, 2009, 10:55 PM > 2009/5/7 Barney Cordoba <barney_cordoba@yahoo.com>: > > > > I just got a shiny new nehalem box and it comes up > with 16 processors with dual quads installed. Is there any > benefit or should hyperthreading be disabled? > > > > Hi. There is a measurable win if hyperthreading is enabled > [1]. > You can switch it off via machdep.hyperthreading_enabled > loader tunable. > > [1] > http://lists.freebsd.org/pipermail/freebsd-stable/2009-January/047460.html > > > -- > wbr, > pluknet I assume you mean hyperthreading-allowed? I set sysctl -a | grep hyper machdep.hyperthreading_allowed: 0 but it still launches 16 cpus. Is that expected? It doesn't seem correct. Barney
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?418018.46727.qm>