Each Athlon MP gets 2.1GB/s of bandwidth to/from the North Bridge in a 760MP system.  Let’s take a two-processor 760MP system for example with two Athlon MPs running at 1.2GHz.  Since all Athlon MPs run at the 133MHz double pumped FSB, the effective clock of the FSB is 266MHz.  Multiply the 266MHz effective frequency of the bus by the 64-bit bus width and you get the bandwidth available to one processor in Gigabits per second; dividing by 8 results in our 2.1 Gigabytes per second figure

So is it fast? Well it's a bit of a tossup compared to the Intel dual systems but it's certainly the fastest thing AMD has ever released and sure as hell cheaper than buying a Xeon. I'm not gonna trust running a server on one of those things just yet though...