It monitors temperatures from various sources, allowing you to adjust the speed fans based on the degrees Celsius that your hardware indicates.
The program also has the capability to monitor S.M.A.R.T. readings for EIDE, SATA and SCSI hard disks and RAID controllers. 

Installing SpeedFan is a simple operation that requires only a couple of seconds. 
Its tabbed interface allows you to view the information in categories, while the system tray indicator displays the temperatures from the hard disk and cores. 

SpeedFan also shows the CPU usage and allows you to configure the fan and voltage settings in according with the detected temperatures. 

In addition, it offers you the possibility to adjust the processor clock values based on various usage scenarios. 

The S.M.A.R.T. feature performs an in-depth analysis on your hard disk and reports various indicators of reliability, thus enabling you to anticipate system failures.