In short - today upgraded my MacPro "Trashcan" to 12 core Xeon.
~ 80% performance increase.
Running Indigo + a lot of plugins + Security Spy (12 HD cameras with AI / HD recognition) - now ~20% CPU load. Used to be ~90%.
Ebay price for a new CPU is around 200$.
Used to be ~3000$
The procedure is quite simple. Highly recommended as a "high-end home automation engine".