Performance in OSX vs. Win 7

[Young Spade]

Your dealing with two complete and separate partitions so I think Windows keeps to itself, although I do see the Mac partition when running Windows and have wondered if I could tell Windows to say defragment the MacOS partition (not going to try it) or some kind of rogue strain could jump to the Mac partition. My impression though is that a Windows virus would not function on the MacOS unless it was written to be a dual system virus. Is it possible? Has it ever happened? I don't know.

Don't know about the possible (It's a computer, it's definitely possible) but it has never happened. I mean, that would require the "program" to know that it's on a partitioned disk... and the whole point of partitioning is to completely (well not completely) separate the drive into multiple, separate parts.