Re: cpuid : Hyper threading siblings: 16?
Am Donnerstag, 8. November 2012 schrieb Philip Ashmore:
> On 08/11/12 19:38, Martin Steigerwald wrote:
> > Am Donnerstag, 8. November 2012 schrieb Philip Ashmore:
> >> But cat /proc/cpuinfo says:
> >> ...
> >> processor : 0
> >> vendor_id : GenuineIntel
> >> cpu family : 6
> >> model : 42
> >> model name : Intel(R) Core(TM) i7-2670QM CPU @ 2.20GHz
> >> stepping : 7
> >> microcode : 0x28
> >> cpu MHz : 2201.000
> >> cache size : 6144 KB
> >> physical id : 0
> >> siblings : 8
> >> core id : 0
> >> cpu cores : 4
> >> ...
> >> I'm sure the system has 4 cores or 8 hyper-threads.
> >> Am I reading it wrong?
> > Regarding the subject of you mail:
> > Thats in total 8 siblings.
> > So you divide 8 / 4 and get 2 siblings per core. I never seen any
> > hyperthreading with more than 2 siblings per core so far.
> > Ciao,
> I guess I wasn't being clear: cpuid tells me I have 16 siblings:
> $ cpuid
> Extended brand string: " Intel(R) Core(TM) i7-2670QM CPU @
> 2.20GHz" CLFLUSH instruction cache line size: 8
> Initial APIC ID: 3
> Hyper threading siblings: 16
I think it is either making things up or getting some wrong information by
For the dualcore CPU in this ThinkPad T520 it tells also 16:
Extended brand string: " Intel(R) Core(TM) i5-2520M CPU @ 2.50GHz"
CLFLUSH instruction cache line size: 8
Initial APIC ID: 3
Hyper threading siblings: 16
dmidecode got it right however:
merkaba:~> dmidecode | grep -i "Thread count"
Thread Count: 4
So I think there is a bug in cpuid.
Martin 'Helios' Steigerwald - http://www.Lichtvoll.de
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