Anyway if the rest of the drive is OK you can disable smart monitoring and go on forever.
This could be read by visitors to the forum, or via a search engine. Its better not to enable smart from the bios, at least thats how i read it.
@Venturer and others, for cooloing if you pc is in a static location. And if you can move the drives outside of the pc case, and extended 80core cables. You could put them in a drive rack or build one (making sure any metal parts do not touch the circuit board).
I have build a simple one as a test out of wood, with countersunk screws with a wide base. Even without a fan they stay cool, a lot cooler than in a AT case. If hot a little 9" or 12" quiet fan blowing on, and through the drive rack would be enough to keep all the drives cool. I did try the other options first AT case fans, fans directed onto hds. The AT cases are not well designed for airflow or for having hot drives inside. Drives that are sandwiched together on top of each other. Biggest failure of drives apart from bad manufactoring componments is heat. Heat is a killer to drives.
I might buy a cd rack that hasn't the central spaces cut out. Chop the rack down to size, and cut the central space to suit hard drive ledges. I haven't yet used any drive mounting screws on the wooden test rack. It is out of the way and never touched. Is there a good reason to screw drives down firmly, if they are out of harms way, and never moved ?