Interesting question – makes me wonder what you plan to do with all that processing power. Which leads me directly to ask you: “What DO you plan to do with all that processing power?”
Right off the bat, I’d say that unless you have an application which is DESIGNED for serious parallel processing, the 12 cpu server would be a waste of money.
My reasoning is that:
1) Servers with more than 4-8 cpu’s are not as common as those with fewer cpu’s (say 2-4) and as such, you’re going to pay more for any given system.
2) Generally, in a production environment, reliability and redundancy go hand in hand, and opting for a simpler configuration.
3) As mentioned above, but to be completely clear, unless you have an application which NEEDS serious parallel processing, you’re going to be better served by having your computing and other serving loads spread out over a number of systems.
If you write back to the group (reply all to your own question) with more details about what you’re planning to do, and why you want a large number of cpu’s, then we as a whole will be in a better position to help you.