Date: Tue, 10 Oct 2006 20:15:36 -0300 From: JoaoBR <joao@matik.com.br> To: freebsd-smp@freebsd.org Subject: Re: Hyperthreading Issues (on Athlon64?) Message-ID: <200610102015.36589.joao@matik.com.br> In-Reply-To: <200610101543.29138.jhb@freebsd.org> References: <20061009114520.1355.qmail@web8608.mail.in.yahoo.com> <200610101555.55558.joao@matik.com.br> <200610101543.29138.jhb@freebsd.org>
next in thread | previous in thread | raw e-mail | index | archive | help
On Tuesday 10 October 2006 16:43, John Baldwin wrote: > On Tuesday 10 October 2006 14:55, JoaoBR wrote: > > On Tuesday 10 October 2006 15:11, Brooks Davis wrote: > > > > My dmesg does not have the line about "Hyperthreading: 2 logical > > > > CPUs", though. =A0But I had been pretty sure the Athlon64 chips did= n't > > > > have any hyperthreading support. =A0Why is the HTT there? > > > > HTT is NOT hyperthreading, HT is and HT does not exist on AMD64 > > Err, no. =A0The HTT there stands for HyperThreading Technology. you say it right: "stands for" in this case But I think it "is" the other way round, in terms of abreviation: HTT =3D Hyper Transport Technology HT =3D Hyper Threading (Technology) http://download.intel.com/design/Pentium4/manuals/24896613.pdf If believe Intel came up with HyperThreading after AMD brought up the term = HTT=20 and so there was no way to call it HTT but "HT Technology" but this story m= ay=20 be wrong. Unluckily (my opinion) in freebsd's i386 kernel (read NOTES) HT technology = is=20 called HTT CPU.=20 Even if this is certainly ok for whom knows it, then an AMD X2 is definitl= y=20 not a hyperthreaded processor but has 2 cores as well as Intel's newer Core= =20 Duo, so HTT for an AMD X2 would be wrong (my opinion again) on AMD DualCore you see Cores per package: 2 <<<<<<< =46reeBSD/SMP: Multiprocessor System Detected: 2 CPUs cpu0 (BSP): APIC ID: 0 cpu1 (AP): APIC ID: 1 on P4 HT you see Logical CPUs per core: 2 <<<<<<< ACPI APIC Table: <INTEL PRODUCT8> =46reeBSD/SMP: Multiprocessor System Detected: 2 CPUs cpu0 (BSP): APIC ID: 0 cpu1 (AP): APIC ID: 1 what then at the end is correct but it does not correct the logic error : HT or HTT is the question but at the end AMD is not HTT, whatever HT or HTT= =20 then is or stands for =2D-=20 Jo=E3o A mensagem foi scaneada pelo sistema de e-mail e pode ser considerada segura. Service fornecido pelo Datacenter Matik https://datacenter.matik.com.br
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200610102015.36589.joao>