FSB is the intermediary between the CPU and the RAM (The northbridge memory controller) however its also communicates between PCI, PCI-E, SATA, IDE, blah controllers.
K8+ does not have a FSB frequency for RAM.
Currently, DDR3 latencies are too high to make them that much faster then DDR2, the only thing going for them is the lower voltages, the K10 problem lies in the small cache, 2mb across 4 cores is just not enough (and remember its a shared cache)
Now going from memory, with the 9850 and E6600 weren't that far apart 15-20 seconds in conversion, which shows a clear lack of ondie cache for precaching data... i think the worst performance problem is the fact that AMD's new architecture has advanced preemptive caching abilities, but doesn't have the required ondie cache available to make use of it, resulting in data swapping which slows the cores processing down.
With no reasonable doubt, kingdom hearts is,,,,,,
err... i mean the extra cache will definitely give a reasonable boost to performance, not to mention the extra mhz gained via the process shrink.