Before taking action with replacing the drive, I'm trying to figure out what's normal.
My Maxtor DM9+ 200GB SATA (6Y200M0) runs 15C to 20C over case ambient. And with case ambient often around 30C, that puts me around 50C or a little more quite often.
Now, you may be thinking case problems (I use as both case fans, all it allows), but then how to explain what happens if I put a Maxtor DM9+ 160GB PATA (6Y160P0) in there instead: it runs at or just a few degrees above case ambient!
Clearly something is out of whack with the larger SATA drive. If platter density or the number of platters have anything to do with it, I list that data below, and I encourage anyone reporting back here to do the same:
6Y200M0 (Sep 2003), Firmware YAR51BW0, Serial Y6...
Therefore 6 heads, 3 platters each 68GB
6Y160P0 (Sep 2003), Firmware YAR41BW0, Serial Y4...
Therefore 4 heads, 2 platters each 80GB