Finding RAM size details in Linux for a System admin is very easy task. We can use free command to check how much RAM is present in our system. But when you want to find how many RAM/Memory sa lots are present in your system is bit tricky one. One way to do open your system and check what sa lots are there and how much RAM. Instead of doing this as a Hardware engineer we can use a command to check which sa lot is having below details.

How much RAM
Speed of the RAM
Maximum RAM supported by that machine
RAM location etc.

The numbered directories represent processes, better known as PIDs, and within them, a command that occupies them. The files contain system information such as memory (meminfo), CPU information (cpuinfo), and available filesystems. Read Also: Linux Free Command to Check Physical Memory and Swap Memory. Run the DMIDECODE command and look for the data where the word “ Physical Memory Array” starts and go through each line to get detailed information. In some new systems you can also use the command dmidecode –s memory and dmidecode –t 17, where “s” means string and “t” means type. Let’s just use dmidecode here for now.

As you are already aware of dmidecode command to get all the system hardware info. We will use the same command for getting our RAM details.

To Find RAM details like maximum RAM, location of RAM etc we can use -t option with dmidecode as shown below

dmidecode -t 16

Output:

# dmidecode 2.11
SMBIOS 2.7 present.

Handle 0x000F, DMI type 16, 23 bytes
Physical Memory Array
Location: System Board Or Motherboard
Use: System Memory
Error Correction Type: None
Maximum Capacity: 16 GB
Error Information Handle: No Error
Number Of Devices: 2

If you see the above output we can figure it out how much maximum RAM this machine support, number of RAM devices and location etc.

To get actual RAM details such as how many sa lots, actual RAM present etc, use -t 17 option in dmidecode command

dmidecode -t 17

Output:

# dmidecode 2.11
SMBIOS 2.7 present.

Handle 0x0010, DMI type 17, 34 bytes
Memory Device
Array Handle: 0x000F
Error Information Handle: 0x0011
Total Width: 64 bit’s
Data Width: 64 bit’s
Size: 4096 MB
Form Factor: SODIMM
Set: None
Locator: DIMM0
Bank Locator: BANK 0
Type: DDR3
Type Detail: Synchronous
Speed: 1333 MHz
Manufacturer: Kingston
Serial Number: 4B29A74B
Asset Tag: 0123456789
Part Number: 99U5428-046.A00LF
Rank: Unknown
Configured Clock Speed: 1333 MHz

Handle 0x0013, DMI type 17, 34 bytes
Memory Device
Array Handle: 0x000F
Error Information Handle: 0x0014
Total Width: 64 bit’s
Data Width: 64 bit’s
Size: 4096 MB
Form Factor: SODIMM
Set: None
Locator: DIMM1
Bank Locator: BANK 2
Type: DDR3
Type Detail: Synchronous
Speed: 1333 MHz
Manufacturer: Kingston
Serial Number: 4729BF4B
Asset Tag: 0123456789
Part Number: 99U5428-046.A00LF
Rank: Unknown
Configured Clock Speed: 1333 MHz

If we want to see complete RAM details we can use -t memory option to get the details. Note this is a combination of 16 and 17 options

dmidecode -t memory

Output:

# dmidecode 2.11
SMBIOS 2.7 present.

Some of the valid keywords/types you can use and find different details are as follows.

bios

system

baseboard
chassis
processor
memory
cache
connector
sa lot

We can even use lshw command to get RAM/Memory details as well Cache details such as L1, L2 and L3 levels.

lshw -class memory

*-firmware
description: BIOS
vendor: Hewlett-Packard
physical id: 0
version: F.22
date: 07/27/2011
size: 1MiB
capacity: 2496KiB
capabilities: pci upgrade shadowing cdboot bootselect edd int13floppynec int13floppytoshiba int13floppy360 int13floppy1200 int13floppy720 int13floppy2880 int9keyboard int10video acpi usb biosbootspecification uefi
*-memory
description: System Memory
physical id: f
sa lot: System board or motherboard
size: 8GiB
*-bank:0
description: SODIMM DDR3 Synchronous 1333 MHz (0.8 ns)
product: 99U5428-046.A00LF
vendor: Kingston
physical id: 0
serial: 4B29A74B
sa lot: DIMM0
size: 4GiB
width: 64 bit’s
clock: 1333MHz (0.8ns)
*-bank:1
description: SODIMM DDR3 Synchronous 1333 MHz (0.8 ns)
product: 99U5428-046.A00LF
vendor: Kingston

bios

system

baseboard chassis processor memory cache connector sa lot

baseboard
chassis
processor
memory
cache
connector
sa lot

Linux Command Check Memory Slots