Hi Sean.
If you are comfortable using the CLI (Command Line Interface), you can get all the information you need on your Fortigate. You have various ways of accessing the CLI: using a program like hyperterminal is one way if you' re connecting via the serial interface, but if you' ve got access via TCP/IP, then just use the icon at the top of the the main status screen (same area you find the icon to log off - I' ve attached a JPG file that shows you where it is).
Once you access the CLI, use the following command:
diagnose hardware sysinfo <component>
Where <component> = cpu, memory, etc... The full list can be obtained by typing in:
diagnose hardware sysinfo ?
I hope this helps you Sean. Please bear in mind that I use a FortiWifi-60A and I don' t know how different the CLI is between the models.
Cheers!
Ed