$ sudo lshw -class memory |grep memory 
  *-memory:0
  *-memory:1
  *-memory:2
  *-memory:3
  *-memory:4 UNCLAIMED
  *-memory:5 UNCLAIMED

$ sudo lshw -class memory |tee memory.txt

  *-firmware
       description: BIOS
       vendor: American Megatrends Inc.
       physical id: 0
       version: 2.0a
       date: 08/25/2016
       size: 64KiB
       capacity: 15MiB
       capabilities: pci upgrade shadowing cdboot bootselect socketedrom edd int13floppy1200 int13floppy720 int13floppy2880 int5printscreen int9keyboard int14serial int17printer acpi usb biosbootspecification uefi
  *-memory:0
       description: System Memory
       physical id: 2a
       slot: System board or motherboard
     *-bank:0
          description: DIMM Synchronous 2400 MHz (0.4 ns)
          product: 18ASF2G72PDZ-2G3B1
          vendor: Micron
          physical id: 0
          serial: 13711909
          slot: P1-DIMMA1
          size: 16GiB
          width: 64 bits
          clock: 2400MHz (0.4ns)
     *-bank:1
          description: DIMM Synchronous 2400 MHz (0.4 ns)
          product: 18ASF2G72PDZ-2G3B1
          vendor: Micron
          physical id: 1
          serial: 137119F5
          slot: P1-DIMMB1
          size: 16GiB
          width: 64 bits
          clock: 2400MHz (0.4ns)
  *-memory:1
       description: System Memory
       physical id: 2d
       slot: System board or motherboard
     *-bank:0
          description: DIMM Synchronous 2400 MHz (0.4 ns)
          product: 18ASF2G72PDZ-2G3B1
          vendor: Micron
          physical id: 0
          serial: 13711900
          slot: P1-DIMMC1
          size: 16GiB
          width: 64 bits
          clock: 2400MHz (0.4ns)
     *-bank:1
          description: DIMM Synchronous 2400 MHz (0.4 ns)
          product: 18ASF2G72PDZ-2G3B1
          vendor: Micron
          physical id: 1
          serial: 137118FF
          slot: P1-DIMMD1
          size: 16GiB
          width: 64 bits
          clock: 2400MHz (0.4ns)
  *-memory:2
       description: System Memory
       physical id: 30
       slot: System board or motherboard
     *-bank:0
          description: DIMM Synchronous 2400 MHz (0.4 ns)
          product: 18ASF2G72PDZ-2G3B1
          vendor: Micron
          physical id: 0
          serial: 13711907
          slot: P2-DIMME1
          size: 16GiB
          width: 64 bits
          clock: 2400MHz (0.4ns)
     *-bank:1
          description: DIMM Synchronous 2400 MHz (0.4 ns)
          product: 18ASF2G72PDZ-2G3B1
          vendor: Micron
          physical id: 1
          serial: 137119F2
          slot: P2-DIMMF1
          size: 16GiB
          width: 64 bits
          clock: 2400MHz (0.4ns)
  *-memory:3
       description: System Memory
       physical id: 33
       slot: System board or motherboard
     *-bank:0
          description: DIMM Synchronous 2400 MHz (0.4 ns)
          product: 18ASF2G72PDZ-2G3B1
          vendor: Micron
          physical id: 0
          serial: 137119F4
          slot: P2-DIMMG1
          size: 16GiB
          width: 64 bits
          clock: 2400MHz (0.4ns)
     *-bank:1
          description: DIMM Synchronous 2400 MHz (0.4 ns)
          product: 18ASF2G72PDZ-2G3B1
          vendor: Micron
          physical id: 1
          serial: 137119F3
          slot: P2-DIMMH1
          size: 16GiB
          width: 64 bits
          clock: 2400MHz (0.4ns)
  *-cache:0
       description: L1 cache
       physical id: 43
       slot: CPU Internal L1
       size: 896KiB
       capacity: 896KiB
       capabilities: internal write-back
       configuration: level=1
  *-cache:1
       description: L2 cache
       physical id: 44
       slot: CPU Internal L2
       size: 3584KiB
       capacity: 3584KiB
       capabilities: internal write-back unified
       configuration: level=2
  *-cache:2
       description: L3 cache
       physical id: 45
       slot: CPU Internal L3
       size: 35MiB
       capacity: 35MiB
       capabilities: internal write-back unified
       configuration: level=3
  *-cache:3
       description: L1 cache
       physical id: 47
       slot: CPU Internal L1
       size: 896KiB
       capacity: 896KiB
       capabilities: internal write-back
       configuration: level=1
  *-cache:4
       description: L2 cache
       physical id: 48
       slot: CPU Internal L2
       size: 3584KiB
       capacity: 3584KiB
       capabilities: internal write-back unified
       configuration: level=2
  *-cache:5
       description: L3 cache
       physical id: 49
       slot: CPU Internal L3
       size: 35MiB
       capacity: 35MiB
       capabilities: internal write-back unified
       configuration: level=3
  *-memory:4 UNCLAIMED
       physical id: 1
  *-memory:5 UNCLAIMED
       physical id: 2

$ sudo dmidecode -t memory |tee dmi.txt

# dmidecode 3.0
Getting SMBIOS data from sysfs.
SMBIOS 3.0 present.

Handle 0x002A, DMI type 16, 23 bytes
Physical Memory Array
    Location: System Board Or Motherboard
    Use: System Memory
    Error Correction Type: Multi-bit ECC
    Maximum Capacity: 128 GB
    Error Information Handle: Not Provided
    Number Of Devices: 2

Handle 0x002B, DMI type 17, 40 bytes
Memory Device
    Array Handle: 0x002A
    Error Information Handle: Not Provided
    Total Width: 72 bits
    Data Width: 64 bits
    Size: 16384 MB
    Form Factor: DIMM
    Set: None
    Locator: P1-DIMMA1
    Bank Locator: P0_Node0_Channel0_Dimm0
    Type: DDR4
    Type Detail: Synchronous
    Speed: 2400 MHz
    Manufacturer: Micron
    Serial Number: 13711909
    Asset Tag: P1-DIMMA1_AssetTag (date:16/31)
    Part Number: 18ASF2G72PDZ-2G3B1 
    Rank: 2
    Configured Clock Speed: 2400 MHz
    Minimum Voltage: Unknown
    Maximum Voltage: Unknown
    Configured Voltage: Unknown

Handle 0x002C, DMI type 17, 40 bytes
Memory Device
    Array Handle: 0x002A
    Error Information Handle: Not Provided
    Total Width: 72 bits
    Data Width: 64 bits
    Size: 16384 MB
    Form Factor: DIMM
    Set: None
    Locator: P1-DIMMB1
    Bank Locator: P0_Node0_Channel1_Dimm0
    Type: DDR4
    Type Detail: Synchronous
    Speed: 2400 MHz
    Manufacturer: Micron
    Serial Number: 137119F5
    Asset Tag: P1-DIMMB1_AssetTag (date:16/31)
    Part Number: 18ASF2G72PDZ-2G3B1 
    Rank: 2
    Configured Clock Speed: 2400 MHz
    Minimum Voltage: Unknown
    Maximum Voltage: Unknown
    Configured Voltage: Unknown

Handle 0x002D, DMI type 16, 23 bytes
Physical Memory Array
    Location: System Board Or Motherboard
    Use: System Memory
    Error Correction Type: Multi-bit ECC
    Maximum Capacity: 128 GB
    Error Information Handle: Not Provided
    Number Of Devices: 2

Handle 0x002E, DMI type 17, 40 bytes
Memory Device
    Array Handle: 0x002D
    Error Information Handle: Not Provided
    Total Width: 72 bits
    Data Width: 64 bits
    Size: 16384 MB
    Form Factor: DIMM
    Set: None
    Locator: P1-DIMMC1
    Bank Locator: P0_Node0_Channel2_Dimm0
    Type: DDR4
    Type Detail: Synchronous
    Speed: 2400 MHz
    Manufacturer: Micron
    Serial Number: 13711900
    Asset Tag: P1-DIMMC1_AssetTag (date:16/31)
    Part Number: 18ASF2G72PDZ-2G3B1 
    Rank: 2
    Configured Clock Speed: 2400 MHz
    Minimum Voltage: Unknown
    Maximum Voltage: Unknown
    Configured Voltage: Unknown

Handle 0x002F, DMI type 17, 40 bytes
Memory Device
    Array Handle: 0x002D
    Error Information Handle: Not Provided
    Total Width: 72 bits
    Data Width: 64 bits
    Size: 16384 MB
    Form Factor: DIMM
    Set: None
    Locator: P1-DIMMD1
    Bank Locator: P0_Node0_Channel3_Dimm0
    Type: DDR4
    Type Detail: Synchronous
    Speed: 2400 MHz
    Manufacturer: Micron
    Serial Number: 137118FF
    Asset Tag: P1-DIMMD1_AssetTag (date:16/31)
    Part Number: 18ASF2G72PDZ-2G3B1 
    Rank: 2
    Configured Clock Speed: 2400 MHz
    Minimum Voltage: Unknown
    Maximum Voltage: Unknown
    Configured Voltage: Unknown

Handle 0x0030, DMI type 16, 23 bytes
Physical Memory Array
    Location: System Board Or Motherboard
    Use: System Memory
    Error Correction Type: Multi-bit ECC
    Maximum Capacity: 128 GB
    Error Information Handle: Not Provided
    Number Of Devices: 2

Handle 0x0031, DMI type 17, 40 bytes
Memory Device
    Array Handle: 0x0030
    Error Information Handle: Not Provided
    Total Width: 72 bits
    Data Width: 64 bits
    Size: 16384 MB
    Form Factor: DIMM
    Set: None
    Locator: P2-DIMME1
    Bank Locator: P1_Node1_Channel0_Dimm0
    Type: DDR4
    Type Detail: Synchronous
    Speed: 2400 MHz
    Manufacturer: Micron
    Serial Number: 13711907
    Asset Tag: P2-DIMME1_AssetTag (date:16/31)
    Part Number: 18ASF2G72PDZ-2G3B1 
    Rank: 2
    Configured Clock Speed: 2400 MHz
    Minimum Voltage: Unknown
    Maximum Voltage: Unknown
    Configured Voltage: Unknown

Handle 0x0032, DMI type 17, 40 bytes
Memory Device
    Array Handle: 0x0030
    Error Information Handle: Not Provided
    Total Width: 72 bits
    Data Width: 64 bits
    Size: 16384 MB
    Form Factor: DIMM
    Set: None
    Locator: P2-DIMMF1
    Bank Locator: P1_Node1_Channel1_Dimm0
    Type: DDR4
    Type Detail: Synchronous
    Speed: 2400 MHz
    Manufacturer: Micron
    Serial Number: 137119F2
    Asset Tag: P2-DIMMF1_AssetTag (date:16/31)
    Part Number: 18ASF2G72PDZ-2G3B1 
    Rank: 2
    Configured Clock Speed: 2400 MHz
    Minimum Voltage: Unknown
    Maximum Voltage: Unknown
    Configured Voltage: Unknown

Handle 0x0033, DMI type 16, 23 bytes
Physical Memory Array
    Location: System Board Or Motherboard
    Use: System Memory
    Error Correction Type: Multi-bit ECC
    Maximum Capacity: 128 GB
    Error Information Handle: Not Provided
    Number Of Devices: 2

Handle 0x0034, DMI type 17, 40 bytes
Memory Device
    Array Handle: 0x0033
    Error Information Handle: Not Provided
    Total Width: 72 bits
    Data Width: 64 bits
    Size: 16384 MB
    Form Factor: DIMM
    Set: None
    Locator: P2-DIMMG1
    Bank Locator: P1_Node1_Channel2_Dimm0
    Type: DDR4
    Type Detail: Synchronous
    Speed: 2400 MHz
    Manufacturer: Micron
    Serial Number: 137119F4
    Asset Tag: P2-DIMMG1_AssetTag (date:16/31)
    Part Number: 18ASF2G72PDZ-2G3B1 
    Rank: 2
    Configured Clock Speed: 2400 MHz
    Minimum Voltage: Unknown
    Maximum Voltage: Unknown
    Configured Voltage: Unknown

Handle 0x0035, DMI type 17, 40 bytes
Memory Device
    Array Handle: 0x0033
    Error Information Handle: Not Provided
    Total Width: 72 bits
    Data Width: 64 bits
    Size: 16384 MB
    Form Factor: DIMM
    Set: None
    Locator: P2-DIMMH1
    Bank Locator: P1_Node1_Channel3_Dimm0
    Type: DDR4
    Type Detail: Synchronous
    Speed: 2400 MHz
    Manufacturer: Micron
    Serial Number: 137119F3
    Asset Tag: P2-DIMMH1_AssetTag (date:16/31)
    Part Number: 18ASF2G72PDZ-2G3B1 
    Rank: 2
    Configured Clock Speed: 2400 MHz
    Minimum Voltage: Unknown
    Maximum Voltage: Unknown
    Configured Voltage: Unknown