S.M.A.R.T. and SSDs

S.M.A.R.T., or SMART, stands for Self-Monitoring, Analysis, and Reporting Technology. SMART is a system used to monitor storage devices, collecting health data from the drive and reporting it to users. It is very useful for ensuring your drive operates in optimal condition. Learn about the history of SMART and how it has evolved to adapt to solid-state drives.

Originally, SMART was a method used by disk drive manufacturers to report the health status of hard disk drives (HDDs) to computers. Although some parameters were listed, each manufacturer could freely choose which parameters to include and what thresholds to set. The Small Form Factor committee (a temporary electronic industry group) attempted to create a standard, which became known as SMART. The initial standard described a communication protocol that ATA hosts could use to monitor and analyze, but it did not specify any metrics or analysis methods.

Many third-party applications can report SMART data. Unfortunately, due to differences between SSDs and HDDs, as well as interactions between the drive and computer, these applications may be inaccurate for some drives or systems.

SMART attributes

Although S.M.A.R.T. status items vary by software, the most important item is “Health”. This is a general indication of error resolution and maintenance. Details are usually listed after the Health score, indicating any areas needing attention. Generally, the following items are included:

• Raw Read Error Rate — number of errors while reading data
  

• Retired Blocks — blocks that have become unsafe for data storage during the drive's lifespan
  

• Power On Hours — total hours the drive has been powered on
  

• Power Cycles — number of times the drive has been turned off and then on again
  

• Device Temperature — current internal temperature of the drive
  

• Total LBAs Written — number of Logical Block Addresses written to
  

• Total LBAs Read — number of Logical Block Addresses read from