Esto es lo que lshw -c memory
( como root ) me da:
*-firmware
description: BIOS
vendor: Acer
physical id: 0
version: V1.41 (01/07/08)
size: 113KiB
capacity: 960KiB
capabilities: isa pci pcmcia pnp upgrade shadowing escd cdboot acpi usb agp biosbootspecification
*-cache:0
description: L1 cache
physical id: 5
slot: L1 Cache
size: 64KiB
capacity: 64KiB
capabilities: asynchronous internal write-back
*-cache:1
description: L2 cache
physical id: 6
slot: L2 Cache
size: 4MiB
capacity: 4MiB
capabilities: burst internal write-back
*-memory
description: System Memory
physical id: 16
slot: System board or motherboard
size: 4GiB
*-bank:0
description: SODIMM DDR2 Synchronous 667 MHz (1.5 ns)
product: SODIMM000
vendor: Mfg 0
physical id: 0
serial: 1234-B0
slot: M1
size: 2GiB
width: 64 bits
clock: 667MHz (1.5ns)
*-bank:1
description: SODIMM DDR2 Synchronous 667 MHz (1.5 ns)
product: SODIMM001
vendor: Mfg 1
physical id: 1
serial: 1234-B1
slot: M2
size: 2GiB
width: 64 bits
clock: 667MHz (1.5ns)
Lo que está buscando es " Memoria del sistema ".