Dual Core VS Dual Processor

Which one is better?(ignoring costs)
I'm thinking of making a dual core system, but woundering if one is better then the other, and how so.

each core in a multi-core cpu shares some common components between each core, thereby causing some contention for cpu components. 

this isn't true for multi-cpu setups.

so, multi-cpu (as opposed to multi-core) is going to be a bit faster.  however, multi-cpu requires more power, more fans, more motherboard space, etc. and the difference in performance is probably not worth it unless you are doing extensive computational work or extremely heavy serving.