My hard disk is not partitioned at all. First, when I bought the computer, OS 9.2 was installed. Then I installed OSX 10.1.1, and then I have upgraded 10.1.2 - 10.1.5 without formatting the hard disk. The only thing I have had to do to is hard disk repair by starting in command line mode and then typing a command, which may sound terrifying to a Mac user, but really is quite simple. I think Classic mode is about the same speed in Jaguar as in OS 10.1.5, and probably Poser is a lot slower than in OS 9. But I prefer to do something else while Poser renders, rather than boot in OS9 .... Everything else about OSX is so much nicer than OS9.