lscpu lists the following

 venki@venki-H8DCL:~$ lscpu
 Architecture:          x86_64
 CPU op-mode(s):        32-bit, 64-bit
 Byte Order:            Little Endian
 CPU(s):                12
 On-line CPU(s) list:   0-11
 Thread(s) per core:    2
 Core(s) per socket:    3   <------ I have 6 cores
 Socket(s):             2
 NUMA node(s):          2
 Vendor ID:             AuthenticAMD
 CPU family:            21
 Model:                 2
 Model name:            AMD Opteron(tm) Processor 4334
 Stepping:              0
 CPU MHz:               1400.000
 CPU max MHz:           3100.0000
 CPU min MHz:           1400.0000
 BogoMIPS:              6199.90
 Virtualization:        AMD-V
 L1d cache:             16K
 L1i cache:             64K
 L2 cache:              2048K
 L3 cache:              6144K
 NUMA node0 CPU(s):     0-5
 NUMA node1 CPU(s):     6-11
  • I have 12 cpu cores. It is a 6 core processor and I have two of them. I can see them in BIOS. This processor doesn't support hyper-threading so 12 physical cores should to be detected. Apr 1, 2016 at 19:55

2 Answers 2


AMD's specs indicate that CPU is six cores and six threads, but you're seeing three cores with two threads each.

Combine that with what appears to be a dual-socket board and your total "CPU count" (4th line), and it does appear to be detecting them all, it's just not displaying the totals the way you expect.

  • You are correct. It effects my parallel programs which looks for physical cores rather than logical cores. Apr 1, 2016 at 19:58

According to the 4th line you have 12 CPU(s).

Maybe you are looking for this information:

cat /proc/cpuinfo

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