Recently I procured a machine with Intel(R) Xeon(R) CPU E5-2650 v3 @ 2.30GHz with 128GB RAM running CentOS 6.7.
The specs in Intel web site show that this processor has 10 cores (20 hyper threaded cores).

However when the output of cat /proc/cpuinfo shows this output 40 times with processor number ranging from 0 to 39.

processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 63
model name : Intel(R) Xeon(R) CPU E5-2650 v3 @ 2.30GHz
stepping : 2
microcode : 42
cpu MHz : 2294.725
cache size : 25600 KB
physical id : 0
siblings : 20
core id : 0
cpu cores : 10
apicid : 0
initial apicid : 0
fpu : yes
fpu_exception : yes
cpuid level : 15
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 pbe syscall nx pdpe1gb rdtscp lm constant_tsc arch_perfmon pebs bts rep_good xtopology nonstop_tsc aperfmperf pni pclmulqdq dtes64 monitor ds_cpl vmx smx est tm2 ssse3 fma cx16 xtpr pdcm pcid dca sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand lahf_lm abm ida arat epb xsaveopt pln pts dts tpr_shadow vnmi flexpriority ept vpid fsgsbase bmi1 avx2 smep bmi2 erms invpcid
bogomips : 4589.45
clflush size : 64
cache_alignment : 64
address sizes : 46 bits physical, 48 bits virtual
power management:

What does this indicate, does my processor have 20 vcores or 40 vcores?

  • 3
    Your machine obviously has 2 of these processors, each supplying 20 virtual cores for a total of 40 on 2x10 physical ones for a total of 20. – Eugen Rieck Mar 23 '16 at 14:25
  • @EugenRieck why not post this as an answer? Seems like this answers the question perfectly. – LPChip Mar 23 '16 at 14:27
  • @shanmuga - Your output shows no evidence that there are 40 virtual cores. – Ramhound Mar 23 '16 at 14:46
  • @EugenRieck how can I confirm if my system has two processors? – shanmuga Mar 23 '16 at 14:53
  • @Ramhound I get the same output is repeated 40 times with different processor number. – shanmuga Mar 23 '16 at 14:55

I'll summarize the comments by @Eugen Rieck and Lưu Vĩnh Phúc.

machine has 2 of these processors, each supplying 20 virtual cores for a total of 40 on 2x10 physical ones for a total of 20.

This can be confirmed by checking the physical id for each core.
In my case there are two distinct physical id 0 and 1, 20 cores in each.

How-to determine the number of physical CPUs under both Windows and Linux

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