How To Get Hardware Information On Linux Using dmidecode Command

dmidecode command reads the system DMI table to display hardware and BIOS information of the server. Apart from getting current configuration of the system, you can also get information about maximum supported configuration of the system using dmidecode. For example, dmidecode gives both the current RAM on the system and the maximum RAM supported by the system.
This dmidecode requires admin permission.

DMI Type id will give information about a particular hardware component
of your system. Following command with type id 4 will get the
information about CPU of the system.

Command as follows: 

# dmidecode -t 4

Following are the different DMI types available.

Type   Information
       ----------------------------------------
          0   BIOS
          1   System
          2   Base Board
          3   Chassis
          4   Processor
          5   Memory Controller
          6   Memory Module
          7   Cache
          8   Port Connector
          9   System Slots
         10   On Board Devices

For more information study the man pages of dmidecode

Thanks to : 

http://www.thegeekstuff.com/2008/11/how-to-get-hardware-information-on-linux-using-dmidecode-command/