Argthtjtr

At the end of this post is my /proc/cpuinfo.

I know the Physical cpu number is 2

grep 'physical id' /proc/cpuinfo|sort|uniq|wc -l

2 

But how many cores does each cpu have?

The 'cpu cores' shows it has 16 cores.

But use this command it shows there are only 8 cores totally.

grep 'core id' /proc/cpuinfo    

core id         : 16

core id         : 0

core id         : 17

core id         : 1

core id         : 25

core id         : 9

core id         : 26

core id         : 10

Displays the number of sibling CPUs on the same physical CPU for architectures which use hyper-threading. It's 16 on my machine. But there are 4 for physical 0 cpu, and 4 on physical 1 cpu. I really confused.

Can anybody help me?

Below is my /proc/cpuinfo

processor   : 0

vendor_id   : GenuineIntel

cpu family  : 6

model       : 12

model name  : Intel(R) Xeon(R) CPU           E5620  @ 2.40GHz

stepping    : 2

cpu MHz     : 2400.191

cache size  : 256 KB

physical id : 1

siblings    : 16

core id     : 16

cpu cores   : 16

fpu     : yes

fpu_exception   : yes

cpuid level : 11

wp      : yes

flags       : 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 ht tm syscall nx lm pni monitor ds_cpl est tm2 cx16 xtpr

bogomips    : 4803.77

clflush size    : 64

cache_alignment : 64

address sizes   : 40 bits physical, 48 bits virtual

power management:



processor   : 1

vendor_id   : GenuineIntel

cpu family  : 6

model       : 12

model name  : Intel(R) Xeon(R) CPU           E5620  @ 2.40GHz

stepping    : 2

cpu MHz     : 2400.191

cache size  : 256 KB

physical id : 0

siblings    : 16

core id     : 0

cpu cores   : 16

fpu     : yes

fpu_exception   : yes

cpuid level : 11

wp      : yes

flags       : 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 ht tm syscall nx lm pni monitor ds_cpl est tm2 cx16 xtpr

bogomips    : 4800.22

clflush size    : 64

cache_alignment : 64

address sizes   : 40 bits physical, 48 bits virtual

power management:



processor   : 2

vendor_id   : GenuineIntel

cpu family  : 6

model       : 12

model name  : Intel(R) Xeon(R) CPU           E5620  @ 2.40GHz

stepping    : 2

cpu MHz     : 2400.191

cache size  : 256 KB

physical id : 1

siblings    : 16

core id     : 17

cpu cores   : 16

fpu     : yes

fpu_exception   : yes

cpuid level : 11

wp      : yes

flags       : 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 ht tm syscall nx lm pni monitor ds_cpl est tm2 cx16 xtpr

bogomips    : 4800.13

clflush size    : 64

cache_alignment : 64

address sizes   : 40 bits physical, 48 bits virtual

power management:



processor   : 3

vendor_id   : GenuineIntel

cpu family  : 6

model       : 12

model name  : Intel(R) Xeon(R) CPU           E5620  @ 2.40GHz

stepping    : 2

cpu MHz     : 2400.191

cache size  : 256 KB

physical id : 0

siblings    : 16

core id     : 1

cpu cores   : 16

fpu     : yes

fpu_exception   : yes

cpuid level : 11

wp      : yes

flags       : 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 ht tm syscall nx lm pni monitor ds_cpl est tm2 cx16 xtpr

bogomips    : 4800.21

clflush size    : 64

cache_alignment : 64

address sizes   : 40 bits physical, 48 bits virtual

power management:



processor   : 4

vendor_id   : GenuineIntel

cpu family  : 6

model       : 12

model name  : Intel(R) Xeon(R) CPU           E5620  @ 2.40GHz

stepping    : 2

cpu MHz     : 2400.191

cache size  : 256 KB

physical id : 1

siblings    : 16

core id     : 25

cpu cores   : 16

fpu     : yes

fpu_exception   : yes

cpuid level : 11

wp      : yes

flags       : 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 ht tm syscall nx lm pni monitor ds_cpl est tm2 cx16 xtpr

bogomips    : 4800.14

clflush size    : 64

cache_alignment : 64

address sizes   : 40 bits physical, 48 bits virtual

power management:



processor   : 5

vendor_id   : GenuineIntel

cpu family  : 6

model       : 12

model name  : Intel(R) Xeon(R) CPU           E5620  @ 2.40GHz

stepping    : 2

cpu MHz     : 2400.191

cache size  : 256 KB

physical id : 0

siblings    : 16

core id     : 9

cpu cores   : 16

fpu     : yes

fpu_exception   : yes

cpuid level : 11

wp      : yes

flags       : 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 ht tm syscall nx lm pni monitor ds_cpl est tm2 cx16 xtpr

bogomips    : 4800.19

clflush size    : 64

cache_alignment : 64

address sizes   : 40 bits physical, 48 bits virtual

power management:



processor   : 6

vendor_id   : GenuineIntel

cpu family  : 6

model       : 12

model name  : Intel(R) Xeon(R) CPU           E5620  @ 2.40GHz

stepping    : 2

cpu MHz     : 2400.191

cache size  : 256 KB

physical id : 1

siblings    : 16

core id     : 26

cpu cores   : 16

fpu     : yes

fpu_exception   : yes

cpuid level : 11

wp      : yes

flags       : 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 ht tm syscall nx lm pni monitor ds_cpl est tm2 cx16 xtpr

bogomips    : 4800.13

clflush size    : 64

cache_alignment : 64

address sizes   : 40 bits physical, 48 bits virtual

power management:



processor   : 7

vendor_id   : GenuineIntel

cpu family  : 6

model       : 12

model name  : Intel(R) Xeon(R) CPU           E5620  @ 2.40GHz

stepping    : 2

cpu MHz     : 2400.191

cache size  : 256 KB

physical id : 0

siblings    : 16

core id     : 10

cpu cores   : 16

fpu     : yes

fpu_exception   : yes

cpuid level : 11

wp      : yes

flags       : 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 ht tm syscall nx lm pni monitor ds_cpl est tm2 cx16 xtpr

bogomips    : 4800.20

clflush size    : 64

cache_alignment : 64

address sizes   : 40 bits physical, 48 bits virtual

power management:

As per Intels' specs for the processor, it's a quad-core CPU (4 distinct cores), each of which is hyperthreading enabled, which makes it appear as an octo-core.

Given that it's a Xeon, you could quite easily have a dual-socket motherboard, which means there's 2 separate chips, each of which has 4 cores, each of which can run two threads, so effectively appears to the OS as a 16-core machine.

Here is a function that I use to check the CPU information.

function CORES(){



  local -i SOCKETS=$(grep -w "physical id" /proc/cpuinfo | sort -u | wc -l)

  [ "${SOCKETS}" -eq 0 ] && SOCKETS="1"

  local -i CORES=$(grep -w "core id" /proc/cpuinfo | sort -u | wc -l)

  [ "${CORES}" -eq 0 ] && CORES="1"

  local -r MODEL=$(grep -w "model name" /proc/cpuinfo | sort -u | awk -F:     '{print $2}')

  local -ir THREADS=$(grep -w "processor" /proc/cpuinfo | sort -u | wc -l)

  local -ir TOTAL_CORES=$(echo $((${SOCKETS}*${CORES})))

  local -ir THREADS_PER_CORE=$(echo $((${THREADS}/${TOTAL_CORES})))



  echo -e "ModelNamet: " $MODEL

  echo -e "Socketstt: " $SOCKETS

  echo -e "Cores/Sockett: " $CORES

  echo -e "Threads/Coret: " $THREADS_PER_CORE

  echo -e "TotalCorest: " $TOTAL_CORES

  echo -e "TotalThreadst: " $THREADS



}

There are three main components to this:

1. Number of Physical CPUs ('physical id')


2. Total number of Cores per Physical CPU ('core id')


3. Total number of Threads per core per physical CPU ('processor')

The 'model name' is just for informational purposes...

The only bug with it is if the 'physical id' does not exist in /proc/cpuinfo, then it throws this error (which I have yet to get around to fixing...):

$ CORES

-bash: 2/0: division by 0 (error token is "0")

ModelName       :  Intel(R) Xeon(R) CPU X5560 @ 2.80GHz

Sockets         :  0

Cores/Socket    :  0

Threads/Core    :  0

TotalCores      :  0

TotalThreads    :  2

edit: fixed.

Hope that helps!

EDIT:
Here is an example of one that has 'physical id' present:

ModelName       :  Intel(R) Xeon(R) CPU X3470 @ 2.93GHz

Sockets         :  2

Cores/Socket    :  1

Threads/Core    :  1

TotalCores      :  2

TotalThreads    :  2

And another

ModelName       :  Intel(R) Xeon(R) CPU E5520 @ 2.27GHz

Sockets         :  2

Cores/Socket    :  2

Threads/Core    :  1

TotalCores      :  4

TotalThreads    :  4

EDIT 2: A big one!

ModelName       :  Intel(R) Xeon(R) CPU X5650 @ 2.67GHz

Sockets         :  2

Cores/Socket    :  6

Threads/Core    :  2

TotalCores      :  12

TotalThreads    :  24

EDIT: The OP's /proc/cpuinfo results

$ CORES

ModelName       :  Intel(R) Xeon(R) CPU E5620 @ 2.40GHz

Sockets         :  2

Cores/Socket    :  8

Threads/Core    :  0

TotalCores      :  16

TotalThreads    :  8

This indicates that you have Hyper Threading disabled somewhere (likely in the bios), which is why you have 0 threads per core. In this case TotalThreads = Cores/Socket. This means you have 8 cores per socket that are not Hyper Threaded.

It seems to me like /proc/cpuinfo is only showing part of your real physical CPU configuration.

Some fields may indicate that your system has 2 CPU sockets, each of which has 16 physical cores :

• 
  physical id goes from 0 to 1, so there would be 2 CPU sockets


• 
  siblings states that you have 16 logical cores per CPU socket


• 
  cpu cores is also 16, which I interpret as the number of physical cores for the CPU specified in physical id. As to this point, I would say that the CPU does not support HyperThreading, but...

According to the spec of Intel E5620 chip, each chip has 4 physical cores, each of which have 2 logical cores thanks to HyperThreading.

That leads me to the conclusion that, from the point of view of your operating system, you only have partial access to the CPU ressources. I would suggest that you are running from a virtualized environment.

Let's see below my /proc/cpuinfo on a virtual machine hosted on a two-CPU Intel E5430-based server (2 CPU sockets, 4 physical cores, no hyperthreading). The operating system only sees core#0 from CPU#0 and core#0 from CPU#1.

processor   : 0

vendor_id   : GenuineIntel

cpu family  : 6

model       : 23

model name  : Intel(R) Xeon(R) CPU           E5430  @ 2.66GHz

stepping    : 10

cpu MHz     : 2659.998

cache size  : 6144 KB

physical id : 0

siblings    : 4

core id     : 0

cpu cores   : 4

apicid      : 0

initial apicid  : 0

fpu     : yes

fpu_exception   : yes

cpuid level : 13

wp      : yes

flags       : fpu vme de pse tsc msr pae mce cx8 apic mtrr pge mca cmov pat pse36 clflush dts     acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx lm constant_tsc arch_perfmon pebs bts rep_good aperfmperf pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm dca sse4_1 xsave lahf_lm tpr_shadow vnmi flexpriority

bogomips    : 5319.99

clflush size    : 64

cache_alignment : 64

address sizes   : 38 bits physical, 48 bits virtual

power management:



processor   : 1

vendor_id   : GenuineIntel

cpu family  : 6

model       : 23

model name  : Intel(R) Xeon(R) CPU           E5430  @ 2.66GHz

stepping    : 10

cpu MHz     : 2659.998

cache size  : 6144 KB

physical id : 1

siblings    : 4

core id     : 0

cpu cores   : 4

apicid      : 4

initial apicid  : 4

fpu     : yes

fpu_exception   : yes

cpuid level : 13

wp      : yes

flags       : fpu vme de pse tsc msr pae mce cx8 apic mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx lm constant_tsc arch_perfmon pebs bts rep_good aperfmperf pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm dca sse4_1 xsave lahf_lm tpr_shadow vnmi flexpriority

bogomips    : 5319.78

clflush size    : 64

cache_alignment : 64

address sizes   : 38 bits physical, 48 bits virtual

power management:

You can parse the /proc/cpuinfo so it is more useful:

paste <(cat /proc/cpuinfo | grep "core id") <(cat /proc/cpuinfo | grep "processor") | sed 's/[[:blank:]]/ /g'

On my machine I see:

core id : 0 processor : 0
core id : 1 processor : 1
core id : 2 processor : 2
core id : 3 processor : 3
core id : 0 processor : 4
core id : 1 processor : 5
core id : 2 processor : 6
core id : 3 processor : 7

So 4 cores each with two threads

"core id" is not necessarily sequential. Here is a grep from a dual socket 12-core with threading (so 48 "cores") G5118. Note the missing core ids:

[qqs43472@cs05r-sc-serv-01 ~]$ cat /proc/cpuinfo  | grep "core id"

core id     : 0

core id     : 1

core id     : 2

core id     : 3

core id     : 4

core id     : 5

core id     : 8

core id     : 9

core id     : 10

core id     : 11

core id     : 12

core id     : 13

core id     : 0

core id     : 1

core id     : 2

core id     : 3

core id     : 4

core id     : 5

core id     : 8

core id     : 9

core id     : 10

core id     : 11

core id     : 12

core id     : 13

core id     : 0

core id     : 1

core id     : 2

core id     : 3

core id     : 4

core id     : 5

core id     : 8

core id     : 9

core id     : 10

core id     : 11

core id     : 12

core id     : 13

core id     : 0

core id     : 1

core id     : 2

core id     : 3

core id     : 4

core id     : 5

core id     : 8

core id     : 9

core id     : 10

core id     : 11

core id     : 12

core id     : 13