HDDScan is a freeware utility for hard drive diagnostics (RAID arrays, Flash USB and SSD drives are also supported). The program can test storage device for errors (Bad-blocks and bad sectors), show S.M.A.R.T. attributes and change some HDD parameters such as AAM, APM, etc.
HDDScan can be useful for performing the regular "health test" for your drive and predicting its degradation, so you will be able to prevent data loss and backup your files before you will have to contact the data recovery service.
Additionally, software can be used as the hard disk temperature monitor and reading/writing benchmark - performance graph is displayed for every test.