Determine maximum memory capacity.
Use a dmidecode utility to decode SMBIOS table contents related to the memory and display using a human-readable format.
$ sudo dmidecode --type memory
# dmidecode 3.2 Getting SMBIOS data from sysfs. SMBIOS 2.7 present. Handle 0x003E, 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: Not Provided Number Of Devices: 2 Handle 0x003F, DMI type 17, 34 bytes Memory Device Array Handle: 0x003E Error Information Handle: Not Provided Total Width: 64 bits Data Width: 64 bits Size: 8192 MB Form Factor: DIMM Set: None Locator: DIMM1 Bank Locator: Not Specified Type: DDR3 Type Detail: Synchronous Speed: 1600 MT/s Manufacturer: 1119 Serial Number: 0010260A10D2 Asset Tag: 01193300 Part Number: S939A2UGS-ITR Rank: 2 Configured Memory Speed: 1600 MT/s Handle 0x0041, DMI type 17, 34 bytes Memory Device Array Handle: 0x003E Error Information Handle: Not Provided Total Width: 64 bits Data Width: 64 bits Size: 8192 MB Form Factor: DIMM Set: None Locator: DIMM2 Bank Locator: Not Specified Type: DDR3 Type Detail: Synchronous Speed: 1600 MT/s Manufacturer: 1119 Serial Number: 0010260A10F2 Asset Tag: 01193300 Part Number: S939A2UGS-ITR Rank: 2 Configured Memory Speed: 1600 MT/s
Narrow down the results.
$ sudo dmidecode --type 16
# dmidecode 3.2 Getting SMBIOS data from sysfs. SMBIOS 2.7 present. Handle 0x003E, 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: Not Provided Number Of Devices: 2
Get only the maximum memory capacity.
$ sudo dmidecode --type memory | awk '/^\tMaximum Capacity/ {print $(NF-1) " " $NF}'
16 GB