check cpu information on Linux from command line

4 commands to check cpu information on Linux

CPU hardware information

The cpu information includes details about the processor, like the architecture, vendor name, model, number of cores, speed of each core etc. There are quite a few commands on linux to get those details about the cpu hardware, and here is a brief about some of the commands.

 1. /proc/cpuinfo

 The /proc/cpuinfo file contains details about individual cpu cores. 

  Output its contents with less or cat.

For example: 

$ less /proc/cpuinfo 

Every processor or core is listed separately the various details about speed, cache size and model name are included in the description.

To count the number of processing units use grep with wc

$ cat /proc/cpuinfo | grep processor | wc -l
4

The number of processors shown by /proc/cpuinfo might not be the actual 

number of cores on the processor. For example a processor with 2 cores 

and hyperthreading would be reported as a processor with 4 cores.

To get the actual number of cores, check the core id for unique values

$ cat /proc/cpuinfo | grep 'core id'
core id         : 0
core id         : 2
core id         : 1
core id         : 3

So there are 4 different core ids. This indicates that there are 4 actual cores.

 

2. lscpu

lscpu is a small and quick command that does not need any options. It would simply print the cpu hardware details in a user-friendly format.

$ lscpu
Architecture:          x86_64
CPU op-mode(s):        32-bit, 64-bit
Byte Order:            Little Endian
CPU(s):                4
On-line CPU(s) list:   0-3
Thread(s) per core:    1
Core(s) per socket:    4
Socket(s):             1
NUMA node(s):          1
Vendor ID:             GenuineIntel
CPU family:            6
Model:                 23
Stepping:              10
CPU MHz:               1998.000
BogoMIPS:              5303.14
Virtualization:        VT-x
L1d cache:             32K
L1i cache:             32K
L2 cache:              2048K
NUMA node0 CPU(s):     0-3

3. dmidecode

The dmidecode command displays some information about the cpu, which includes the socket type, vendor name and various flags.

$ sudo dmidecode -t 4
# dmidecode 2.12
SMBIOS 2.4 present.

Handle 0x0000, DMI type 4, 35 bytes
Processor Information
        Socket Designation: LGA 775
        Type: Central Processor
        Family: Pentium D
        Manufacturer: Intel(R) Corporation
        ID: 7A 06 01 00 FF FB EB BF
        Signature: Type 0, Family 6, Model 23, Stepping 10
        Flags:
                FPU (Floating-point unit on-chip)
                VME (Virtual mode extension)
                DE (Debugging extension)
                PSE (Page size extension)
                TSC (Time stamp counter)
                MSR (Model specific registers)
                PAE (Physical address extension)
                MCE (Machine check exception)
                CX8 (CMPXCHG8 instruction supported)
                APIC (On-chip APIC hardware supported)
                SEP (Fast system call)
                MTRR (Memory type range registers)
                PGE (Page global enable)
                MCA (Machine check architecture)
                CMOV (Conditional move instruction supported)
                PAT (Page attribute table)
                PSE-36 (36-bit page size extension)
                CLFSH (CLFLUSH instruction supported)
                DS (Debug store)
                ACPI (ACPI supported)
                MMX (MMX technology supported)
                FXSR (FXSAVE and FXSTOR instructions supported)
                SSE (Streaming SIMD extensions)
                SSE2 (Streaming SIMD extensions 2)
                SS (Self-snoop)
                HTT (Multi-threading)
                TM (Thermal monitor supported)
                PBE (Pending break enabled)
        Version: Intel(R) Core(TM)2 Quad CPU    Q8400  @ 2.66GHz
        Voltage: 1.6 V
        External Clock: 333 MHz
        Max Speed: 4000 MHz
        Current Speed: 2666 MHz
        Status: Populated, Enabled
        Upgrade: Socket LGA775
        L1 Cache Handle: 0x0003
        L2 Cache Handle: 0x0001
        L3 Cache Handle: Not Provided
        Serial Number: Not Specified
        Asset Tag: Not Specified
        Part Number: Not Specified

4. cpuid

The cpuid command fetches CPUID information about Intel and AMD x86 processors.
The program can be installed with apt on ubuntu

$ sudo apt-get install cpuid