Ubuntu – ny difference between processor and core

cpu

The following two command seems to give me different information about the same hardware

srs@ubuntu:~$ cat /proc/cpuinfo | grep -e processor -e cores
processor   : 0
cpu cores   : 4
processor   : 1
cpu cores   : 4
processor   : 2
cpu cores   : 4
processor   : 3
cpu cores   : 4

srs@ubuntu:~$ sudo dmidecode -t processor 
# dmidecode 2.9
SMBIOS 2.6 present.

Handle 0x0004, DMI type 4, 42 bytes
Processor Information
    Socket Designation: LGA1155
    Type: Central Processor
    Family: <OUT OF SPEC>
    Manufacturer: Intel            
    ID: A7 06 02 00 FF FB EB BF
    Version: Intel(R) Core(TM) i5-2500K CPU @ 3.30GHz       
    Voltage: 1.0 V
    External Clock: 100 MHz
    Max Speed: 3800 MHz
    Current Speed: 3300 MHz
    Status: Populated, Enabled
    Upgrade: Other
    L1 Cache Handle: 0x0005
    L2 Cache Handle: 0x0006
    L3 Cache Handle: 0x0007
    Serial Number: To Be Filled By O.E.M.
    Asset Tag: To Be Filled By O.E.M.
    Part Number: To Be Filled By O.E.M.
    Core Count: 4
    Core Enabled: 1
    Characteristics:
        64-bit capable

Until today I thought I had a single processor with 4 independent cores. I also thought that within each core can be used different threads.

Mitch has given to the way to find out that I have got the Single socket Quad Core (Example 3):

srs@ubuntu:~$ cat /proc/cpuinfo | grep -e processor -e "model name" -e "cache size" -e "physical id" -e "siblings" -e "core id" -e "cpu cores"
processor   : 0
model name  : Intel(R) Core(TM) i5-2500K CPU @ 3.30GHz
cache size  : 6144 KB
physical id : 0
siblings    : 4
core id     : 0
cpu cores   : 4
processor   : 1
model name  : Intel(R) Core(TM) i5-2500K CPU @ 3.30GHz
cache size  : 6144 KB
physical id : 0
siblings    : 4
core id     : 1
cpu cores   : 4
processor   : 2
model name  : Intel(R) Core(TM) i5-2500K CPU @ 3.30GHz
cache size  : 6144 KB
physical id : 0
siblings    : 4
core id     : 2
cpu cores   : 4
processor   : 3
model name  : Intel(R) Core(TM) i5-2500K CPU @ 3.30GHz
cache size  : 6144 KB
physical id : 0
siblings    : 4
core id     : 3
cpu cores   : 4

Now I can understand that there are much more different kinds of processors that I never thought. Thanks

Best Answer

A multi-core processor is a single processor that have more than 1 cores running at same speed.

Dual CPU = Means 2 physical CPU's

Dual Core = Means that a single CPU that have two cores allowing it to deal with two threads at once

For example, a Quad Core Processor that runs at speed of 3GHz , will have 4 cores running at that speed. What that means that at a given time the CPU can process data 4 times in 4 separate cores.

Newer applications and games are coded in a way that benefit from Multiore Processors.

For more information you can look at Understanding Linux /proc/cpuinfo

Related Question