Multicore vs multiCPU

Wincomputing brings us a brief article on the differences between multiple CPU systems and multiple core systems. This isn't directly related to gaming, but it is interesting. I've not delved into hardware too much, as it's not necessary for me to know the details of performance for my career path.

Anyway, I had always just assumed that multi-CPU would be the better option, but I didn't consider what was explained in this article. Essentially, efficiency is driven down with the required cross-processor communication (organizing and assigning threads). Multicores allow for for less lag in this communication, resulting in better performance.

And the bit about AMD integrating a Northbridge chipset into their X2 explains the larger size, larger price, and larger efficiency. I guess AMD is currently where it's at for PC gamers?