System: DMI decode
(last edit: 2008-02-22)
                   Here's how to find out what hardware is in your computer / server/

Or as the tool itself describes:

Dmidecode is a tool or dumping a computer's DMI (some say SMBIOS) table
contents in a human-readable format. The output contains a description of the
system's hardware components, as well as other useful pieces of information
such as serial numbers and BIOS revision.

install it from /usr/port/sysutils/dmidecode

just run it without any options:

root@# dmidecode

sample output (stripped):

System Information
        Manufacturer: Supermicro
        Product Name: PDSMi

Processor Information
        Version: Intel(R) Core(TM)2 Duo CPU 2.13GH
        Current Speed: 2130 MHz