Date: Wed, 18 May 2005 18:11:32 -0700 From: "David O'Brien" <obrien@freebsd.org> To: Astrodog <astrodog@gmail.com> Cc: freebsd-amd64@freebsd.org Subject: Re: FreeBSD on dual core Opterons - stupid buildworld test Message-ID: <20050519011132.GB64608@dragon.NUXI.org> In-Reply-To: <2fd864e05051811442152fa@mail.gmail.com> References: <428B6FC1.3000907@fsn.hu> <1116437340.69035.0.camel@hood.oook.cz> <20050518180521.GB9719@odin.ac.hmc.edu> <200505181441.39457.jkim@niksun.com> <2fd864e05051811442152fa@mail.gmail.com>
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On Wed, May 18, 2005 at 11:44:13AM -0700, Astrodog wrote: > > > > > http://people.fsn.hu/~bra/bl45p/dmesg.boot > > > > > Hyperthreading: 2 logical CPUs > > > > > > > > So dual-core Opterons report into system as Hyperthreading? > > > > Uncool. > > > > > > What the AMD reps said at a session I attended last year is that > > > they report as supporting hyper threading, but set another bit to > > > say that they are actually real cores. We probably need to find > > > out what that bit is. .. > > Opteron reports Hyperthreading, because it tries to take advantage of > the licencing benifit. Keep in mind, HT P4s are counted as a single > CPU for the most part, in a licence. Opteron may not. By acting as > though its a HT processor, it gets that same benifit. Partical truth. AMD also sets the HTT bit so that legacy OS's (ie, those released before AMD dual-core) will take some advantage of the 2nd core(s). -- -- David (obrien@FreeBSD.org)
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