问题
I generally know that the more the number of processors the more processes (watching a movie, playing some game, running firefox with youtube playing a Simpson's episode, all simultaneously) you can have simultaneously going without your computer slowing down. But I want to know how to make sense of the linux commands cpuinfo and lscpu.
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: 42
Stepping: 7
CPU MHz: 1600.000
BogoMIPS: 6800.18
Virtualization: VT-x
L1d cache: 32K
L1i cache: 32K
L2 cache: 256K
L3 cache: 8192K
NUMA node0 CPU(s): 0-7
and cpuinfo:
===== Processor composition =====
Processor name : Quad-Core AMD Opteron(tm) Processor 2354
Packages(sockets) : 2
Cores : 8
Processors(CPUs) : 8
Cores per package : 4
Threads per core : 1
===== Processor identification =====
Processor Thread Id. Core Id. Package Id.
0 0 0 0
1 0 1 0
2 0 2 0
3 0 3 0
4 0 0 1
5 0 1 1
6 0 2 1
7 0 3 1
===== Placement on packages =====
Package Id. Core Id. Processors
0 0,1,2,3 0,1,2,3
1 0,1,2,3 4,5,6,7
What exactly are they telling me. A dual core to me means two core per processor. I can see 8 CPU(s) listed. But what is the difference between thread and cores. I can see 2 Thread(s) per core. And what is a socket? I could not google a place where things are explained but there are plenty of places which tell you to use cpuinfo/lscpu.
回答1:
What you call "core" is technically a "physical core", aka socket aka package.
A physical core is "virtually splitted" into logical cores (listed simply as "core(s)" by cpuinfo/lscpu.
So your system has 2 physical cores, each one divided into 4 logical cores. This sums up into 8 logical cores.
A similar question on tomshw: http://www.tomshardware.co.uk/answers/id-1850932/difference-physical-core-logical-core.html
Hyperthreading: http://en.m.wikipedia.org/wiki/Hyper-threading
回答2:
A socket is on the motherboard, where you plug the processor inside and have a fan cooling it.
cpuinfo on your machine says that you have a motherboard with 2 sockets and 2 processors, which are each a Quad-Core AMD Opteron(tm) Processor 2354. So together you have 8 cores (2x quad (4) core) and also 8 threads available.
you ran lscpu on a different machine which has only one processor on the motherboard. This one is an intel quad core with Hyper-Threading.
回答3:
A socket is a physical plug on your motherboard. A core is a physical part of a computer, while a thread is a specific path of execution on a core. This answer explains threads really well.
lscpu - http://manpages.courier-mta.org/htmlman1/lscpu.1.html
cpuinfo - http://www.richweb.com/cpu_info
EDIT: whoops, got network sockets mixed in there for some reason. Just kidding.
来源：https://stackoverflow.com/questions/22548159/making-sense-of-cpu-info