How to use the command dmidecode (with examples)

dmidecode is a command-line tool used to display the DMI (Desktop Management Interface) or SMBIOS (System Management BIOS) table contents in a human-readable format. It is typically used to retrieve hardware-related information from a computer system. The command requires root privileges and can provide various details such as BIOS version, system serial number, BIOS information, CPU information, and memory information.

Use case 1: Show all DMI table contents

Code:

sudo dmidecode

Motivation:

This use case is useful when you want to gather comprehensive information about the hardware installed on a system. It provides a detailed report containing information about the system’s BIOS, CPU, memory, and other components.

Explanation:

The sudo command is used to execute dmidecode with root privileges. The dmidecode command retrieves and displays the entire DMI table contents in a readable format.

Example output:

# dmidecode 3.2
Getting SMBIOS data from sysfs.
SMBIOS 3.4.0 present.

Handle 0x0000, DMI type 0, 26 bytes
BIOS Information
        Vendor: Dell Inc.
        Version: 1.2.3
        Release Date: 01/01/2022
        BIOS Revision: 1.5
        Firmware Revision: 1.7

Handle 0x0001, DMI type 1, 27 bytes
System Information
        Manufacturer: Dell Inc.
        Product Name: Inspiron 1234
        Version: 1.0.0
        Serial Number: ABCD1234
        UUID: 01234567-89AB-CDEF-0123-456789ABCDEF
        Wake-up Type: Power Switch
        SKU Number: 0123456789
        Family: Inspiron

...

Use case 2: Show the BIOS version

Code:

sudo dmidecode -s bios-version

Motivation:

This use case is helpful when you only need to retrieve the BIOS version information from a system. It provides a quick way to obtain this specific detail.

Explanation:

The sudo command is used to execute dmidecode with root privileges. The -s option is used to specify that we want to display a specific string value. In this case, we are requesting the BIOS version. The argument bios-version denotes the specific string we are interested in.

Example output:

1.2.3

Use case 3: Show the system’s serial number

Code:

sudo dmidecode -s system-serial-number

Motivation:

When you need to identify a specific system by its serial number, this use case comes in handy. It allows you to quickly retrieve the system’s unique identifier.

Explanation:

The sudo command is used to execute dmidecode with root privileges. The -s option is used to specify that we want to display a specific string value. In this case, we are requesting the system’s serial number. The argument system-serial-number denotes the specific string we are interested in.

Example output:

ABCD1234

Use case 4: Show BIOS information

Code:

sudo dmidecode -t bios

Motivation:

When you require detailed information about the system’s BIOS, this use case is useful. It provides specific information related to the BIOS, such as the vendor, version, release date, and firmware revision.

Explanation:

The sudo command is used to execute dmidecode with root privileges. The -t option is used to specify the type of information we want to retrieve. In this case, we are requesting information related to the BIOS. The argument bios denotes the specific type we are interested in.

Example output:

BIOS Information
        Vendor: Dell Inc.
        Version: 1.2.3
        Release Date: 01/01/2022
        BIOS Revision: 1.5
        Firmware Revision: 1.7

Use case 5: Show CPU information

Code:

sudo dmidecode -t processor

Motivation:

When you need to gather detailed information about the CPU installed on a system, this use case is valuable. It provides specific information related to the CPU, such as the socket designation, manufacturer, and version.

Explanation:

The sudo command is used to execute dmidecode with root privileges. The -t option is used to specify the type of information we want to retrieve. In this case, we are requesting information related to the processor (CPU). The argument processor denotes the specific type we are interested in.

Example output:

Processor Information
        Socket Designation: CPU Socket
        Type: Central Processor
        Family: Core i7
        Manufacturer: Intel
        Version: Intel(R) Core(TM) i7-9700K CPU @ 3.60GHz
        Max Speed: 3600 MHz
        ...

Use case 6: Show memory information

Code:

sudo dmidecode -t memory

Motivation:

When you want to obtain information about the memory (RAM) installed on a system, this use case is valuable. It provides specific details about the memory modules, such as the type, size, and speed.

Explanation:

The sudo command is used to execute dmidecode with root privileges. The -t option is used to specify the type of information we want to retrieve. In this case, we are requesting information related to memory. The argument memory denotes the specific type we are interested in.

Example output:

Memory Device
        Array Handle: 0x0001
        Error Information Handle: Not Provided
        Total Width: 64 bits
        Data Width: 64 bits
        Size: 16 GB
        Form Factor: Unknown
        ...

Conclusion

dmidecode is a powerful command-line tool that allows you to retrieve hardware-related information from a system’s DMI or SMBIOS table. By using various options and arguments, you can obtain specific details about the BIOS, CPU, memory, and more. With the examples provided, you can utilize dmidecode to gather valuable information for troubleshooting, system audits, or general hardware knowledge.