My good old F720 seems to have run out of gas.  It is now running at 100% CPU utilization all the time and application performance has gotten really bad.

I’m hoping to be able to upgrade the head and still use the three drive shelves.  But I’m wondering why I’m seeing this poor performance all of a sudden and if it really is normal behavior.

The F720 has a gigabit network interface but network usage never goes over 10%.  When network usage gets to 5%, which would mean 50 Mbps, the CPU hits 100% and stays there.

Is that really the maximum capacity of an F720?

The three drive shelves are:

Shelf 0: EDM  Kernel Version : 0.4      App. Version : 0.0

            Shelf 1: VEM  Kernel Version : 2.5      App. Version : 3.1

            Shelf 2: VEM  Kernel Version : 2.5      App. Version : 3.1

What options do I have for replacing the head with a faster one that would work with these shelves?