As per the title:
How can I tell how much RAM is installed on a FreeBSD server?
I usually look it up through dmesg messages, like
su-3.2# grep memory /var/run/dmesg.boot usable memory = 8571846656 (8174 MB) avail memory = 8270299136 (7887 MB) su-3.2#
A quick and dirty way is to run the "top" utility.
If you want to know the size and count of memory sticks in the machine, install dmidecode from the ports tree. It will read the DMI information from the Motherboard and give you lots of hardware configuration information.
I use the
free -m command on Linux. Here is an article on different ways of getting this, including a FreeBSD replacement for the
free command: http://www.cyberciti.biz/faq/freebsd-command-to-get-ram-information/