_$: dmidecode --type memory
# dmidecode 2.11
SMBIOS 2.5 present.
Handle 0x001B, DMI type 16, 15 bytes # Memory array
Physical Memory Array
Location: System Board Or Motherboard
Use: System Memory
Error Correction Type: None
Maximum Capacity: 8 GB
Error Information Handle: Not Provided
Number Of Devices: 4
Handle 0x001C, DMI type 17, 27 bytes # Slot 1
Memory Device
Array Handle: 0x001B
Error Information Handle: 0xFF01
Total Width: 40968 bits
Data Width: 41032 bits
Size: 1024 MB
Form Factor: DIMM
Set: 1
Locator: DIMM1
Bank Locator: DIMM 0
Type: DDR2
Type Detail: Synchronous
Speed: 800 MHz
Manufacturer: Not Specified
Serial Number: Not Specified
Asset Tag: Not Specified
Part Number: Not Specified
Handle 0x001D, DMI type 17, 27 bytes # Slot 2
Memory Device
Array Handle: 0x001B
Error Information Handle: 0xFF01
Total Width: 41480 bits
Data Width: 41544 bits
Size: 1024 MB
Form Factor: DIMM
Set: 1
Locator: DIMM2
Bank Locator: DIMM 1
Type: DDR2
Type Detail: Synchronous
Speed: 800 MHz
Manufacturer: Not Specified
Serial Number: Not Specified
Asset Tag: Not Specified
Part Number: Not Specified
Handle 0x001E, DMI type 17, 27 bytes # Slot 3
Memory Device
Array Handle: 0x001B
Error Information Handle: 0xFF01
Total Width: 41992 bits
Data Width: 42056 bits
Size: 1024 MB
Form Factor: DIMM
Set: 1
Locator: DIMM3
Bank Locator: DIMM 2
Type: DDR2
Type Detail: Synchronous
Speed: 800 MHz
Manufacturer: Not Specified
Serial Number: Not Specified
Asset Tag: Not Specified
Part Number: Not Specified
Handle 0x001F, DMI type 17, 27 bytes # Slot 4
Memory Device
Array Handle: 0x001B
Error Information Handle: 0xFF01
Total Width: 42504 bits
Data Width: 42568 bits
Size: 1024 MB
Form Factor: DIMM
Set: 1
Locator: DIMM4
Bank Locator: DIMM 3
Type: DDR2
Type Detail: Synchronous
Speed: 800 MHz
Manufacturer: Not Specified
Serial Number: Not Specified
Asset Tag: Not Specified
Part Number: Not Specified
_$: lshw -class memory
...
*-memory
description: System Memory
physical id: 1b
slot: System board or motherboard
size: 4GiB
*-bank:0
description: DIMM DDR2 Synchronous 800 MHz (1.2 ns)
physical id: 0
slot: DIMM1
size: 1GiB
width: 40968 bits
clock: 800MHz (1.2ns)
*-bank:1
description: DIMM DDR2 Synchronous 800 MHz (1.2 ns)
physical id: 1
slot: DIMM2
size: 1GiB
width: 41480 bits
clock: 800MHz (1.2ns)
*-bank:2
description: DIMM DDR2 Synchronous 800 MHz (1.2 ns)
physical id: 2
slot: DIMM3
size: 1GiB
width: 41992 bits
clock: 800MHz (1.2ns)
*-bank:3
description: DIMM DDR2 Synchronous 800 MHz (1.2 ns)
physical id: 3
slot: DIMM4
size: 1GiB
width: 42504 bits
clock: 800MHz (1.2ns)
_$: free
total used free shared buffers cached
Mem: 3918744 905032 3013712 0 221176 465696
-/+ buffers/cache: 218160 3700584
Swap: 3905528 0 3905528