If your machine install the IGNITE software you can use print_manifest , If not you can use cstm (Command line interface to the Support Tool Manager)
bash> echo "selclass qualifier memory;info;wait;infolog" | /usr/sbin/cstm | grep 'Total Configured' Total Configured Memory : 143360 MB
Addition from mE
# top
or
# glance
or
# /usr/sbin/dmesg | grep -i Physical
or
sam > Performance Monitors > System Properties > Memory
@Eriek
Yoi, semuanya bisa, tapi "glance" jarang nemuin lagi neh bro, hehehehe, lisensinya mahal.
eniwey thanks berat.