Hi all, I have a last-gen iMac that I'm going to upgrade from the base 2GB of memory to 4GB. Looking through the system profiler yesterday to check the memory configuration, I noticed that it has 800MHz RAM, but a 1067MHz FSB. So, two questions before I do the upgrade: First, is there a such thing as a DDR2 PC2-8500 SO-DIMM? I haven't been able to find this, even on Newegg. Second, if the answer to the first is yes, will there be a significant performance difference by putting that in rather than PC2-6400?