That's what kept me from installing the Hitachi 8MB buffer 7200RPM 7K60 drive in my G4 iBook - heat issue concerns. I couldn't find any info on the web about it so I use the drive in an external Wiebetech case. Would love to use it as an internal drive - if you come across info saying it's safe, please let the us know. Rick > I did forget to mention, that things seemed to get a little bit hotter > on the > bottom, but its hard to tell only by feel. May have to consider that > the ibook > might get a bit more hot, and the fan may turn on more often.