Para verificar en Linux la memoria RAM presente en el sistema, hay varias formas:
[root@localhost ~]# free -m
total used free shared buffers cached
Mem: 985 760 225 0 134 207
-/+ buffers/cache: 419 566
Swap: 7034 0 7034
[root@localhost ~]#
Mucha más información:
[root@localhost ~]# cat /proc/meminfo
MemTotal: 1009576 kB
MemFree: 230468 kB
Buffers: 137432 kB
Cached: 212416 kB
SwapCached: 36 kB
Active: 498112 kB
Inactive: 153356 kB
HighTotal: 105152 kB
HighFree: 636 kB
LowTotal: 904424 kB
LowFree: 229832 kB
SwapTotal: 7203832 kB
SwapFree: 7203672 kB
Dirty: 460 kB
Writeback: 0 kB
AnonPages: 301612 kB
Mapped: 105656 kB
Slab: 46164 kB
PageTables: 6348 kB
NFS_Unstable: 0 kB
Bounce: 0 kB
CommitLimit: 7708620 kB
Committed_AS: 777356 kB
VmallocTotal: 114680 kB
VmallocUsed: 9184 kB
VmallocChunk: 105076 kB
HugePages_Total: 0
HugePages_Free: 0
HugePages_Rsvd: 0
Hugepagesize: 4096 kB
[root@localhost ~]#