What are Advantages of power on self test?

Answer 1

Advantages of Power on Self TestPower On Self-Test (POST) is the process of using software or embedded firmware to perform start-up operations using algorithms to determine if the computer's components are fully functional and ready to use. Though the POST can take more time during boot-up, the process can help assure that damaged hardware does not destroy or manipulate a computer's files and data in a manner that is destructive. The POST can warn the user that it has detected a fault and can notify the user that the hardware fault has occurred and action needs to be taken to prevent any future or current data destruction.

Examples of Power On Self Tests include the "walking ones" test that is used to check ram chips as well as the data bus for errors. Patterns are written into ram and then read back to assure that the data remains accurate. Error Correction Code (ECC) testing on ram is also tested to assure that the memory controllers ECC mechanism is functioning correctly to automatically detect and correct single bit ram errors.

Many hard drives now have the ability to warn the computer before they are about to crash. For example, the S.M.A.R.T (Self-Monitoring, Analysis and Reporting Technology; often written as SMART) system is in place on many computers to help protect data by performing self-monitoring and then pre-warning the computer doing the POST that a fault has been detected.

POST is often implemented in the boot code or the BIOS of a computer's firmware. Many motherboards come with a BIOS that provides options for fast boot which often skips many of the power on self tests.

Companies that develop boot code are often responsible for designing the POST software as part of the boot up or start code.