To check the speed and type of RAM (random access memory) on a Linux system, you can use the dmidecode command. The dmidecode command is a utility that allows you to extract information from the system's DMI (Desktop Management Interface) table, which stores hardware and system information.
To use the dmidecode command, open a terminal and enter the following command:
sudo dmidecode -t 17
The -t 17 option tells the dmidecode command to display information about the system's memory devices. The output of the command will show the size, speed, type, and other details about each memory device installed on the system.
For example, the output might look something like this:
# dmidecode 3.2
Getting SMBIOS data from sysfs.
SMBIOS 2.6 present.
Handle 0x0034, DMI type 17, 27 bytes
Memory Device
Array Handle: 0x0033
Error Information Handle: Not Provided
Total Width: 64 bits
Data Width: 64 bits
Size: 4096 MB
Form Factor: DIMM
Set: None
Locator: DIMM_A1
Bank Locator: BANK 0
Type: DDR4
Type Detail: Synchronous
Speed: 2666 MT/s
Manufacturer: Unknown
Serial Number: Unknown
Asset Tag: Unknown
Part Number: HMA851S6AFR6N-UH
Handle 0x0036, DMI type 17, 27 bytes
Memory Device
Array Handle: 0x0033
Error Information Handle: Not Provided
Total Width: 64 bits
Data Width: 64 bits
Size: 4096 MB
Form Factor: DIMM
Set: None
Locator: DIMM_A2
Bank Locator: BANK 2
Type: DDR4
Type Detail: Synchronous
Speed: 2666 MT/s
Manufacturer: Unknown
Serial Number: Unknown
Asset Tag: Unknown
Part Number: HMA851S6AFR6N-UH
...
In this example, the output shows that the system has two memory devices, each with a size of 4096 MB, a type of DDR4, and a speed of 2666 MT/s.
Keep in mind that the dmidecode command may not work on all systems, as it requires access to the system's BIOS. Some systems may not have the necessary access rights to the BIOS, or the BIOS may not be compatible with the dmidecode command. Additionally, some systems may not have the necessary hardware or software to support the dmidecode command.