And then you can turn to the Big Guns—ProSoft Engineering's $99 Drive Genius 3 or Micromat's $50 (currently on sale for $30) Checkmate or $100 Techtool Pro 7. Drive Genius and Techtool Pro can not only monitor but also repair your drive (though no software utility can repair a problem with the drive's hardware). Checkmate is a monitoring application, but one that goes beyond simple S.M.A.R.T. status reporting. It will additionally check your Mac's RAM, laptop battery, volume structure, RAID status, the integrity of the hard drive's surface (looking for bad block, for example), file structure, I/O check, and Power On Self Test.
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