S.M.A.R.T. is actually a failure predication method based on a device varying from a defined set of thresholds. The idea is an industry wide continuation of PFA (predictive failure analysis) implemented and invented by IBM for its mainframe computers. The first company to implement S.M.A.R.T. technology on desktop PC's was Compaq Computer with their DFP (drive failure prediction).

A drive that is S.M.A.R.T. compliant has a series of tests embedded on the controller of the HDD. The data is constantly collected and monitored for variations within vendor specific thresholds. These tests are designed to predict the impending degradation or failure of a drive. For instance, if a drive is designed to spin at 3500 RPM and the manufactures threshold is +/- 100 RPM, the drive may be within threshold for a year, but as the drive ages the RPM's begin to fluctuate and before long are at 3300 RPM. Once that happens, an error is logged and a message is sent to the System Administrator and/or the user. The drive can now be scheduled for replacement before the condition gets worse and becomes catastrophic.

The various tests and thresholds that govern pass or fail are vendor specific and usually proprietary. The type of failures monitored by SMART include head and servo issues which result in read and seek errors, motor failure or bearing problems that result in spin up problems, excessive bad sectors and thermal testing. The faults are categorized into predictable and unpredictable, with the unpredictable usually being catastrophic. Unpredictable faults are normally electronics related or caused by static electricity or from handling. Testing and data collection can be in an on-line or off-line mode.

In the on-line mode, data is collected during idle times.

In the off-line mode the drive is required to respond to commands directly from the host and interrupt any operations.

Active SMART Monitor has automatic settings for monitoring the drive in on-line status as well as test now button for immediate off-line testing and data collection where supported. In order to make the implementation of S.M.A.R.T. practical, the system has to be able to alert the user, or in the case of a network, the system administrator of a potential failure.

To date the only way to utilize the S.M.A.R.T. technology is through the newer BIOS or with a simple desktop application that notifies the user of a failure. Most of these utilities are manufacturer specific and run under DOS. We go a step further. Active SMART Monitor runs natively under Windows 95/98/ME/NT/2000/XP and has easy to use messaging options where notifications can be sent via e-mail, network.

Active SMART Monitor also monitors more than two physical drives, and in fact can monitor all of the drives in your system.