It is Ubuntu 16.04

$ uname -a

Linux m-x170 4.4.0-42-generic #62-Ubuntu SMP Fri Oct 7 23:11:45 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux

The processor used is Xeon E3 1245 v5 that is spec'ed as quad core 8 threads per core.

dmidecode -t processor shows



Core Count: 4

Core Enabled: 4

Thread Count: 8

Characteristics:

    64-bit capable

    Multi-Core

    Hardware Thread

    Execute Protection

    Enhanced Virtualization

    Power/Performance Control

And lscpu shows



$ lscpu

Architecture:          x86_64

CPU op-mode(s):        32-bit, 64-bit

Byte Order:            Little Endian

CPU(s):                8

On-line CPU(s) list:   0-7

Thread(s) per core:    2

Core(s) per socket:    4

Socket(s):             1

NUMA node(s):          1

Vendor ID:             GenuineIntel

CPU family:            6

Model:                 94

Model name:            Intel(R) Xeon(R) CPU E3-1245 v5 @ 3.50GHz

And when queried about HTT, it is there too.

$ sudo dmidecode | grep HTT

        HTT (Multi-threading)

The question is: Why is lscpu showing 2 threads per core where as the dmidecode reports 8 threads (meaning 8 per core)?