Mostly, you will find maximum supported RAM by your system from the BIOS, Product catalog, or manuals. Here is the simple, yet useful trick, to find out maximum supported RAM using Dmidecode without opening the system chassis or referring the BIOS, product catalogs.
### What is Dmidecode? ###
As you may know, **Dmidecode** is a tool for dumping a computer’s DMI (some say SMBIOS) table contents in a human-readable format. This table contains a description of the system’s hardware components, as well as other useful pieces of information such as serial numbers and BIOS revision. Using Dmidecode, you can retrieve this information without having to probe for the actual hardware.
### Find out the maximum RAM supported by your system ###
Make sure you have installed dmidecode on your system. I think it will be automatically installed while installing your OS, but I am not sure though.
**On Deb based system:**
sudo apt-get install dmidecode
**On RPM based system:**
sudo yum install dmidecode
**On SUSE/openSUSE:**
sudo zypper in dmidecode
Well, we installed dmidecode. Let us find out the maximum RAM supported. To do that, enter the following command:
sudo dmidecode -t 16
**Sample output:**
# dmidecode 2.12
SMBIOS 2.6 present.
Handle 0x0014, DMI type 16, 15 bytes
Physical Memory Array
Location: System Board Or Motherboard
Use: System Memory
Error Correction Type: None
Maximum Capacity: 16 GB
Error Information Handle: Not Provided
Number Of Devices: 2
As you see in the above output, my system will support RAM upto 16GB, and it has two RAM slots. Pretty easy, isn’t it?
Well, let us find out the currently installed RAM details.
sudo dmidecode -t 17
**Sample output:**
# dmidecode 2.12
SMBIOS 2.6 present.
Handle 0x0017, DMI type 17, 28 bytes
Memory Device
Array Handle: 0x0014
Error Information Handle: 0x0000
Total Width: Unknown
Data Width: Unknown
Size: No Module Installed
Form Factor: DIMM
Set: None
Locator: DIMM_B
Bank Locator: BANK 2
Type: Unknown
Type Detail: None
Speed: Unknown
Manufacturer: Not Specified
Serial Number: Not Specified
Asset Tag: Not Specified
Part Number: Not Specified
Rank: Unknown
Handle 0x0015, DMI type 17, 28 bytes
Memory Device
Array Handle: 0x0014
Error Information Handle: 0x0000
Total Width: 64 bits
Data Width: 64 bits
Size: 4096 MB
Form Factor: SODIMM
Set: None
Locator: DIMM_A
Bank Locator: BANK 0
Type: DDR3
Type Detail: Synchronous
Speed: 1067 MHz
Manufacturer: 014F
Serial Number: 00092AF2
Asset Tag: 54114000
Part Number: JM1066KSN-4G
Rank: Unknown
As per the above output, I have installed one RAM in DIMM slot 1. The RAM size is **4GB**, and it’s type and speed is **DDR3** and **1067 MHz** respectively.
Also, we can have the complete RAM details using the following commands.
sudo dmidecode -t memory
sudo dmidecode -t memory | less
sudo dmidecode -t memory | more
**Sample output:**
# dmidecode 2.12
SMBIOS 2.6 present.
Handle 0x0014, DMI type 16, 15 bytes
Physical Memory Array
Location: System Board Or Motherboard
Use: System Memory
Error Correction Type: None
Maximum Capacity: 16 GB
Error Information Handle: Not Provided
Number Of Devices: 2
Handle 0x0017, DMI type 17, 28 bytes
Memory Device
Array Handle: 0x0014
Error Information Handle: 0x0000
Total Width: Unknown
Data Width: Unknown
Size: No Module Installed
Form Factor: DIMM
Set: None
Locator: DIMM_B
Bank Locator: BANK 2
Type: Unknown
Type Detail: None
Speed: Unknown
Manufacturer: Not Specified
Serial Number: Not Specified
Asset Tag: Not Specified
Part Number: Not Specified
Rank: Unknown
Handle 0x0015, DMI type 17, 28 bytes
Memory Device
Array Handle: 0x0014
Error Information Handle: 0x0000
Total Width: 64 bits
Data Width: 64 bits
Size: 4096 MB
Form Factor: SODIMM
Set: None
Locator: DIMM_A
Bank Locator: BANK 0
Type: DDR3
Type Detail: Synchronous
Speed: 1067 MHz
Manufacturer: 014F
Serial Number: 00092AF2
Asset Tag: 54114000
Part Number: JM1066KSN-4G
Rank: Unknown
Curious to know the complete system details such as Motherboard, Memory, Bios etc? Well, enter the following command to get all details.
sudo dmidecode
**Sample output:**
# dmidecode 2.12
SMBIOS 2.6 present.
48 structures occupying 2173 bytes.
Table at 0x000EB840.
Handle 0xDA00, DMI type 218, 251 bytes
OEM-specific Type
Header and Data:
DA FB 00 DA B2 00 0D 5F 0F 37 40 7D 00 00 00 00
00 7E 00 01 00 00 00 DC 01 00 80 02 00 DD 01 00
80 03 00 75 01 01 80 01 00 76 01 02 80 01 00 2D
01 03 80 01 00 2E 01 03 80 00 00 81 01 07 80 00
00 82 01 07 80 01 00 83 01 08 80 00 00 84 01 08
80 01 00 85 01 06 80 00 00 86 01 06 80 01 00 58
02 05 80 00 00 57 02 05 80 01 00 9C 00 02 00 01
00 9B 00 02 00 00 00 8A 01 03 00 01 00 89 01 03
00 00 00 7F 01 04 00 00 00 80 01 04 00 01 00 53
01 05 00 00 00 52 01 05 00 01 00 7B 01 06 00 00
00 7C 01 06 00 01 00 94 01 07 00 00 00 93 01 07
00 01 00 7D 00 08 00 00 00 2D 00 09 00 01 00 2E
00 09 00 00 00 6E 00 0A 00 00 00 95 00 0B 00 01
00 96 00 0B 00 00 00 2F 02 0C 00 01 00 30 02 0C
00 00 00 50 02 0D 00 00 00 51 02 0D 00 01 00 52
02 0D 00 02 00 FF FF 00 00 00 00
Handle 0xDA01, DMI type 218, 59 bytes
OEM-specific Type
Header and Data:
DA 3B 01 DA B2 00 0D 5F 0F 37 40 53 02 0D 00 03
00 54 02 0D 00 04 00 56 02 0D 00 05 00 4B 01 0E
00 01 00 4A 01 0E 00 00 00 EA 00 0F 00 01 00 EB
00 0F 00 00 00 FF FF 00 00 00 00
Handle 0x0004, DMI type 4, 42 bytes
Processor Information
Socket Designation: CPU 1
Type: Central Processor
Family: Core i3
Manufacturer: Intel
ID: A7 06 03 01 FF FB AB BE
Signature: Type 0, Family 6, Model 42, Stepping 7
Flags:
FPU (Floating-point unit on-chip)
VME (Virtual mode extension)
DE (Debugging extension)
PSE (Page size extension)
TSC (Time stamp counter)
MSR (Model specific registers)
PAE (Physical address extension)
MCE (Machine check exception)
CX8 (CMPXCHG8 instruction supported)
APIC (On-chip APIC hardware supported)
SEP (Fast system call)
MTRR (Memory type range registers)
PGE (Page global enable)
MCA (Machine check architecture)
CMOV (Conditional move instruction supported)
PAT (Page attribute table)
PSE-36 (36-bit page size extension)
CLFSH (CLFLUSH instruction supported)
DS (Debug store)
ACPI (ACPI supported)
MMX (MMX technology supported)
FXSR (FXSAVE and FXSTOR instructions supported)
SSE (Streaming SIMD extensions)
SSE2 (Streaming SIMD extensions 2)
SS (Self-snoop)
HTT (Multi-threading)
TM (Thermal monitor supported)
PBE (Pending break enabled)
Version: Intel(R) Core(TM) i3-2350M CPU @ 2.30GHz
Voltage: 1.1 V
External Clock: 100 MHz
Max Speed: 2300 MHz
Current Speed: 2300 MHz
Status: Populated, Enabled
Upgrade: Other
L1 Cache Handle: 0x0005
L2 Cache Handle: 0x0006
L3 Cache Handle: 0x0007
Serial Number: To Be Filled By O.E.M.
Asset Tag: To Be Filled By O.E.M.
Part Number: To Be Filled By O.E.M.
Core Count: 2
Core Enabled: 1
Thread Count: 2
Characteristics:
64-bit capable
Handle 0x0005, DMI type 7, 19 bytes
Cache Information
Socket Designation: L1-Cache
Configuration: Enabled, Not Socketed, Level 1
Operational Mode: Write Back
Location: Internal
Installed Size: 64 kB
Maximum Size: 64 kB
Supported SRAM Types:
Other
Installed SRAM Type: Other
Speed: Unknown
Error Correction Type: None
System Type: Unified
Associativity: 8-way Set-associative
Handle 0x0006, DMI type 7, 19 bytes
Cache Information
Socket Designation: L2-Cache
Configuration: Enabled, Not Socketed, Level 2
Operational Mode: Varies With Memory Address
Location: Internal
Installed Size: 512 kB
Maximum Size: 512 kB
Supported SRAM Types:
Other
Installed SRAM Type: Other
Speed: Unknown
Error Correction Type: None
System Type: Unified
Associativity: 8-way Set-associative
Handle 0x0007, DMI type 7, 19 bytes
Cache Information
Socket Designation: L3-Cache
Configuration: Enabled, Not Socketed, Level 3
Operational Mode: Varies With Memory Address
Location: Internal
Installed Size: 3072 kB
Maximum Size: 3072 kB
Supported SRAM Types:
Other
Installed SRAM Type: Other
Speed: Unknown
Error Correction Type: None
System Type: Unified
Associativity: Other
Handle 0x0008, DMI type 8, 9 bytes
Port Connector Information
Internal Reference Designator: J1A1
Internal Connector Type: None
External Reference Designator: PS2Mouse
External Connector Type: PS/2
Port Type: Mouse Port
Handle 0x0009, DMI type 8, 9 bytes
Port Connector Information
Internal Reference Designator: J1A1
Internal Connector Type: None
External Reference Designator: Keyboard
External Connector Type: PS/2
Port Type: Keyboard Port
Handle 0x000A, DMI type 8, 9 bytes
Port Connector Information
Internal Reference Designator: J2A2B
Internal Connector Type: None
External Reference Designator: Video
External Connector Type: DB-15 female
Port Type: Video Port
Handle 0x000B, DMI type 8, 9 bytes
Port Connector Information
Internal Reference Designator: J3A1
Internal Connector Type: None
External Reference Designator: USB1
External Connector Type: Access Bus (USB)
Port Type: USB
Handle 0x000C, DMI type 8, 9 bytes
Port Connector Information
Internal Reference Designator: J3A1
Internal Connector Type: None
External Reference Designator: USB2
External Connector Type: Access Bus (USB)
Port Type: USB
Handle 0x000D, DMI type 8, 9 bytes
Port Connector Information
Internal Reference Designator: J3A1
Internal Connector Type: None
External Reference Designator: USB3
External Connector Type: Access Bus (USB)
Port Type: USB
Handle 0x000E, DMI type 8, 9 bytes
Port Connector Information
Internal Reference Designator: J5A1
Internal Connector Type: None
External Reference Designator: LAN
External Connector Type: RJ-45
Port Type: Network Port
Handle 0x000F, DMI type 9, 17 bytes
System Slot Information
Designation: J6B2
Type: x16 PCI Express
Current Usage: In Use
Length: Long
ID: 0
Characteristics:
3.3 V is provided
Opening is shared
PME signal is supported
Bus Address: 0000:00:01.0
Handle 0x0010, DMI type 9, 17 bytes
System Slot Information
Designation: J6B1
Type: x1 PCI Express
Current Usage: In Use
Length: Short
ID: 1
Characteristics:
3.3 V is provided
Opening is shared
PME signal is supported
Bus Address: 0000:00:1c.3
Handle 0x0012, DMI type 11, 5 bytes
OEM Strings
String 1: Dell System
String 2: 5[0003]
String 3: 13[P18F]
Handle 0x0013, DMI type 12, 5 bytes
System Configuration Options
Option 1: To Be Filled By O.E.M.
Handle 0x001C, DMI type 21, 7 bytes
Built-in Pointing Device
Type: Touch Pad
Interface: Bus Mouse
Buttons: 2
Handle 0x001D, DMI type 22, 26 bytes
Portable Battery
Location: Sys. Battery Bay
Manufacturer: Sanyo
Serial Number: 5390
Name: DELL 4YRJH22
Chemistry: Lithium Ion
Design Capacity: 45000 mWh
Design Voltage: 10800 mV
SBDS Version: 1.0
Maximum Error: 2%
SBDS Manufacture Date: 2012-02-28
OEM-specific Information: 0x00000001
Handle 0x001E, DMI type 32, 20 bytes
System Boot Information
Status: No errors detected
Handle 0x0020, DMI type 27, 12 bytes
Cooling Device
Type: Fan
Status: OK
OEM-specific Information: 0x00000000
Handle 0x0021, DMI type 28, 20 bytes
Temperature Probe
Description: CPU Internal Temperature
Location: Processor
Status: OK
Maximum Value: 127.0 deg C
Minimum Value: 0.0 deg C
Resolution: 1.000 deg C
Tolerance: 0.5 deg C
Accuracy: Unknown
OEM-specific Information: 0x00000000
Handle 0xB000, DMI type 176, 5 bytes
OEM-specific Type
Header and Data:
B0 05 00 B0 00
Handle 0xB100, DMI type 177, 12 bytes
OEM-specific Type
Header and Data:
B1 0C 00 B1 1A 0E 00 00 00 00 00 00
Handle 0x0025, DMI type 209, 12 bytes
OEM-specific Type
Header and Data:
D1 0C 25 00 00 00 00 03 05 01 00 03
Handle 0x0026, DMI type 210, 12 bytes
OEM-specific Type
Header and Data:
D2 0C 26 00 00 00 00 03 05 20 01 03
Handle 0x0027, DMI type 211, 13 bytes
OEM-specific Type
Header and Data:
D3 0D 27 00 01 00 00 00 00 02 03 04 04
Strings:
Front
Handle 0x0028, DMI type 212, 57 bytes
OEM-specific Type
Header and Data:
D4 39 28 00 70 00 71 00 01 49 50 48 9C 00 49 FC
01 9B 00 49 FC 00 7F 01 4A FB 04 80 01 4A FB 00
53 01 4A F7 08 52 01 4A F7 08 7B 01 4A EF 10 7C
01 4A EF 10 FF FF 00 00 00
Handle 0x002A, DMI type 217, 8 bytes
OEM-specific Type
Header and Data:
D9 08 2A 00 01 02 00 00
Strings:
Handle 0x002B, DMI type 219, 11 bytes
OEM-specific Type
Header and Data:
DB 0B 2B 00 00 01 02 03 00 04 05
Strings:
Handle 0x002C, DMI type 220, 22 bytes
OEM-specific Type
Header and Data:
DC 16 2C 00 01 F0 00 00 02 F0 00 00 00 00 03 F0
04 F0 00 00 00 00
Handle 0x002D, DMI type 221, 19 bytes
OEM-specific Type
Header and Data:
DD 13 2D 00 00 00 00 00 00 03 00 00 00 00 00 00
00 00 00
Handle 0x002E, DMI type 222, 16 bytes
OEM-specific Type
Header and Data:
DE 10 2E 00 01 08 FF FF 00 00 00 00 00 00 00 00
Handle 0x0014, DMI type 16, 15 bytes
Physical Memory Array
Location: System Board Or Motherboard
Use: System Memory
Error Correction Type: None
Maximum Capacity: 16 GB
Error Information Handle: Not Provided
Number Of Devices: 2
Handle 0x0016, DMI type 20, 19 bytes
Memory Device Mapped Address
Starting Address: 0x00000000000
Ending Address: 0x000FFFFFFFF
Range Size: 4 GB
Physical Device Handle: 0x0015
Memory Array Mapped Address Handle: 0x0018
Partition Row Position: 1
Interleave Position: 1
Interleaved Data Depth: 1
Handle 0x0017, DMI type 17, 28 bytes
Memory Device
Array Handle: 0x0014
Error Information Handle: 0x0000
Total Width: Unknown
Data Width: Unknown
Size: No Module Installed
Form Factor: DIMM
Set: None
Locator: DIMM_B
Bank Locator: BANK 2
Type: Unknown
Type Detail: None
Speed: Unknown
Manufacturer: Not Specified
Serial Number: Not Specified
Asset Tag: Not Specified
Part Number: Not Specified
Rank: Unknown
Handle 0x0018, DMI type 19, 15 bytes
Memory Array Mapped Address
Starting Address: 0x00000000000
Ending Address: 0x000FFFFFFFF
Range Size: 4 GB
Physical Array Handle: 0x0014
Partition Width: 2
Handle 0x002F, DMI type 13, 22 bytes
BIOS Language Information
Language Description Format: Abbreviated
Installable Languages: 1
eng
Currently Installed Language: eng
Handle 0x0030, DMI type 131, 64 bytes
OEM-specific Type
Header and Data:
83 40 30 00 31 00 00 00 00 00 00 00 00 00 00 00
F8 00 4B 1C FF FF FF FF 01 00 00 00 00 00 07 00
AD 04 04 00 00 00 00 00 C8 00 FF FF 00 00 00 00
00 00 00 00 32 00 00 00 76 50 72 6F 00 00 00 00
Handle 0x0029, DMI type 216, 9 bytes
OEM-specific Type
Header and Data:
D8 09 29 00 01 02 01 00 00
Strings:
INTEL
0000
Handle 0x0000, DMI type 0, 24 bytes
BIOS Information
Vendor: Dell Inc.
Version: A05
Release Date: 08/03/2012
Address: 0xF0000
Runtime Size: 64 kB
ROM Size: 2048 kB
Characteristics:
MCA is supported
PCI is supported
BIOS is upgradeable
BIOS shadowing is allowed
ESCD support is available
Boot from CD is supported
Selectable boot is supported
BIOS ROM is socketed
EDD is supported
5.25"/1.2 MB floppy services are supported (int 13h)
3.5"/720 kB floppy services are supported (int 13h)
3.5"/2.88 MB floppy services are supported (int 13h)
