Determining RAM memory size and type on Linux

Sometime, you need to know about RAM memory size and type, number of RAM memory slots and capasity of every slot. This information is needed when you want to increase your RAM memory. Right now, too many RAM memory size, RAM memory type and memory clock rate in market. Memory type such as SoDIMM, DDR, DDR2, DDR3, SDRAM, etc (see http://home.pacbell.net/dbk4297/memory_what_kind.html)

Without open your computer casing, you can get detail information about your RAM memory. On Linux, you can use command line "dmidecode". And with special option, you can analyze information more easy.

Code :
# dmidecode --type memory

Example with Laptop Lenovo 3000 v100 :

[root@msmunir1 ~]# dmidecode --type memory
# dmidecode 2.9
SMBIOS 2.4 present.

Handle 0x0010, DMI type 16, 15 bytes
Physical Memory Array
Location: System Board Or Motherboard
Use: System Memory
Error Correction Type: None
Maximum Capacity: 2 GB
Error Information Handle: Not Provided
Number Of Devices: 2

Handle 0x0011, DMI type 17, 27 bytes
Memory Device
Array Handle: 0x0010
Error Information Handle: No Error
Total Width: Unknown
Data Width: Unknown
Size: No Module Installed
Form Factor: SODIMM
Set: 1
Locator: M1
Bank Locator: Bank 0
Type: DDR2
Type Detail: Synchronous
Speed: Unknown
Manufacturer: Not Specified
Serial Number: Not Specified
Asset Tag: Not Specified
Part Number: Not Specified

Handle 0x0012, DMI type 17, 27 bytes
Memory Device
Array Handle: 0x0010
Error Information Handle: No Error
Total Width: 32 bits
Data Width: 32 bits
Size: 512 MB
Form Factor: SODIMM
Set: 1
Locator: M2
Bank Locator: Bank 1
Type: DDR2
Type Detail: Synchronous
Speed: Unknown
Manufacturer: Not Specified
Serial Number: Not Specified
Asset Tag: Not Specified
Part Number: Not Specified

[root@msmunir1 ~]#

In this example above, you will see :
Number of RAM Slot : 2
Number of slot used : 1 (on slot M2 or second slot)
Size of RAM memory : 512 MB
Type of RAM memory : SODIMM

Correlation between speed and type of RAM Memory :
133 Mhz = PC-133
333 Mhz = PC-2700
400 Mhz = PC-3200
533 Mhz = PC-4200
667 Mhz = PC-5300
800 Mhz = PC-6400

Type of RAM Memory :
DDR Memory for PC
SDRAM Memory for PC
DDR2 Memory for PC
SO-DIMM Memory for Notebook
SO-DIMM SDRAM for Notebook
DDR Memory for Server
SDRAM Memory for Server
DDR2 Memory for Server
FB DIMM DDR2 for Server

Capacity of RAM Memory : 128 MB, 256 MB, 512 MB, 1 GB, 2 GB
(Visit www.v-gen.web.id)
by.msmunir@batan.go.id