Figuring out how many real cpus, cpu cores, and logical cpus

[Ivan Voras]

Aragon Gouveia wrote:
> Hi,
> 
> I'm struggling to figure out if my BSD system is detecting the correct
> properties about my CPU.
> 
> What I've figured out so far is that FreeBSD is seeing 1 physical CPU, with
> 1 core, and 2 logical CPUs.  However, I am fairly certain this CPU should
> have multiple cores (atleast two).
> 
> How do I check how many cores a CPU has vs. how many are actually detected? 
> I do not have physical access to the machine nor any record of this
> system's purchase invoice, so I need to go on what software tells me.
> 
> Bootup dmesg is below.

>   Origin = "GenuineIntel"  Id = 0xf4a  Stepping = 10
>   Features=0xbfebfbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CLFLUSH,DTS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,PBE>
>   Features2=0x649d<SSE3,RSVD2,MON,DS_CPL,EST,CNXT-ID,CX16,xTPR>
>   AMD Features=0x20100000<NX,LM>
>   AMD Features2=0x1<LAHF>
>   Logical CPUs per core: 2
> real memory  = 3757834240 (3583 MB)
> avail memory = 3682926592 (3512 MB)
> ACPI APIC Table: <DELL   PE BKC  >
> FreeBSD/SMP: Multiprocessor System Detected: 2 CPUs
>  cpu0 (BSP): APIC ID:  0
>  cpu1 (AP): APIC ID:  1

This is most likely a hyperthreaded CPU from an older NetBurst (pentium
4-style) Xeon generation, so the displayed information is correct: you
have one socket, with single core CPU in it, which supports
hyperthreading so it presents itself as two CPUs. You probably also need
to enable machdep.hyperthreading_allowed sysctl (if you have it).

If you still doubt it, you can send the model number or look it up
yourself in
http://en.wikipedia.org/wiki/List_of_Intel_Xeon_microprocessors .

sysutils/dmidecode utility could also help you.

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