Date: Thu, 12 Oct 2006 09:24:48 -0400 From: John Baldwin <jhb@freebsd.org> To: freebsd-smp@freebsd.org Cc: JoaoBR <joao@matik.com.br> Subject: Re: Hyperthreading Issues (on Athlon64?) Message-ID: <200610120924.48482.jhb@freebsd.org> In-Reply-To: <200610102015.36589.joao@matik.com.br> References: <20061009114520.1355.qmail@web8608.mail.in.yahoo.com> <200610101543.29138.jhb@freebsd.org> <200610102015.36589.joao@matik.com.br>
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On Tuesday 10 October 2006 19:15, JoaoBR wrote: > 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 d= idn'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. >=20 > you say it right: "stands for" in this case >=20 > But I think it "is" the other way round, in terms of abreviation: >=20 > HTT =3D Hyper Transport Technology > HT =3D Hyper Threading (Technology) I don't think this really bothers anyone. > Even if this is certainly ok for whom knows it, then an AMD X2 is defini= tly=20 > not a hyperthreaded processor but has 2 cores as well as Intel's newer Co= re=20 > Duo, so HTT for an AMD X2 would be wrong (my opinion again) You didn't read anything I said earlier. When dual-core came out, to make = it easier for OS's to detect it (probably Windows), AMD made a dual-core CPU look just like an Intel CPU with 2 hyperthreads including using the CPUID HT flag in cpuid that _Intel_ had reserved. Even ports/misc/cpuid calls the flag HT. Sheesh. =2D-=20 John Baldwin
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