I think it's more 5-platter 7200rpm drives vs. 3T drives, inherently (I think there may be a 4-platter 3T now). An old 5-platter 75GXP might kill it, too.
This is why I avoid 4 and 5 platter drives like the plague. They tend to overheat and die faster no matter how you try to cool them, and I'm not sure why: I'm pretty sure the drives aren't intentionally defective, and I doubt the manufacturers haven't compensated for the additional load on the spindle motor and the power bus.
