Date: Wed, 21 Sep 2005 17:19:34 -0400 From: Jung-uk Kim <jkim@FreeBSD.org> To: freebsd-amd64@FreeBSD.org, kono@kth.se Cc: freebsd-hardware@FreeBSD.org Subject: Re: Dual core AMD64 4400+ X2 works fine on Abit AV8 Message-ID: <200509211719.36890.jkim@FreeBSD.org> In-Reply-To: <200509212259.07082.kono@kth.se> References: <200509211147.17279.kono@kth.se> <43317E28.1090404@fsn.hu> <200509212259.07082.kono@kth.se>
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On Wednesday 21 September 2005 04:59 pm, Alexander Konovalenko wrote: > On Wednesday 21 September 2005 17.37, Attila Nagy wrote: > > Alexander Konovalenko wrote: > > > 2) recompiled and installed 5.4-STABLE kernel with "options > > > SMP", then I tested it with old single core CPU > > > CPU: AMD Athlon(tm) 64 X2 Dual Core Processor 4400+ > > > (2247.42-MHz K8-class CPU) Origin = "AuthenticAMD" Id = > > > 0x20f32 Stepping = 2 > > > Features=0x178bfbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP > > >,MTRR,PGE, MCA,C MOV,PAT,PSE36,CLFLUSH,MMX,FXSR,SSE,SSE2,HTT> > > > Features2=0x1<SSE3> > > > AMD > > > Features=0xe2500800<SYSCALL,NX,MMX+,<b25>,LM,3DNow+,3DNow> > > > Hyperthreading: 2 logical CPUs > > > > Can this "I see hyperthreading, while there is no hyperthreading" > > cause performance degradation, for example by HTT defaults to off > > in the recent 5.x builds? If you are using 6.0 or above, you can try this patch: http://people.freebsd.org/~jkim/multicore.diff I believe the old patch still applies to 5.4: http://docs.freebsd.org/cgi/mid.cgi?200505182007.28631.jkim Jung-uk Kim > I just made some grep in /usr/src and > found /usr/src/sys/amd64/amd64/identcpu.c, near the line #293: > ..... > /* > * If this CPU supports hyperthreading then > mention * the number of logical CPU's it contains. */ > if (cpu_feature & CPUID_HTT && > (cpu_procinfo & CPUID_HTT_CORES) >> 16 > > 1) printf("\n Hyperthreading: %d logical CPUs", (cpu_procinfo & > CPUID_HTT_CORES) >> 16); ... > > I don't know all details but seem that cpu_feature contain > CPUID_HTT bit.... Yes, it does. Backward compatibility... Jung-uk Kim > /Alexander Konovalenko > > +46-8-5537-8142 (office) > +46-7-3752-2116 > http://daemon.nanophys.kth.se/~kono > > Royal Institute of Technology (KTH) > Nanostructure Physics Department, Albanova > Roslagstullsbacken 21 > 10691 Stockholm > Sweden > > > _______________________________________________ > freebsd-amd64@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-amd64 > To unsubscribe, send any mail to > "freebsd-amd64-unsubscribe@freebsd.org"
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