enough of freewares... this one is not a "must have" and i don't use it often, yet it's the best tool for monitoring your hard drives.
Hard Disk Sentinel (HDSentinel) is a multi-OS SSD and HDD monitoring and analysis software. Its goal is to find, test, diagnose and repair hard disk drive problems, report and display SSD and HDD health, performance degradations and failures. Hard Disk Sentinel gives complete textual description, tips and displays/reports the most comprehensive information about the hard disks and solid state disks inside the computer and in external enclosures (USB / e-SATA). Many different alerts and report options are available to ensure maximum safety of your valuable data.