What is SMART and how is it useful to gauge my drive's health?

SMART relies on the values provided by the drive’s controller to determine the amount of writes, temperatures, reallocated blocks, and more. Of course, if for some reason (hardware or software fault) the SMART values being reported are incorrect, they are not reliable. This theoretic problem however should not keep you from checking your SMART data every once in a while, or have a software like SSD Utility checking them for you and warn in case of a rapidly degrading drive. To avoid misreported and misinterpreted values, it is highly recommended to use SSD Utility or CLOUT to read out SMART data.

SSD Utility Interface

SSD Utility features different icons to label the attributes:
- Endurance (Grey box with clock): This is relevant to judge the drive’s remaining endurance
- Functionality (Green box with checkmark): Indicates if the drive functions as expected
- Information (light blue ball with an i): Useful but not necessarily crucial information
Accumulated Runtime Bad Blocks
This value will slowly rise as your drive wears out. Unless the value suddenly jumps in a short amount of time, this is nothing to worry about. At the time of this value rising, the Available OP Sector Count (see below) would decrease.
Power-On Hours Count
The total “mileage” of a drive. This SSD has been powered on for a total of 262 hours.
Power Cycle Count
The amount of power cycles that happened for a drive. This drive has been power cycled for 69 times. This includes regular power cycles as well as software resets called by the host system.
Available OP Sector Count
All current OCZ SSDs feature OP (Overprovisioning), a reserved bit of NAND capacity that is being used for various different maintenance duties as well as reserve for bad blocks.
Power Cycle Count (unplanned)
This number would go up if a drive is being removed from a power source unexpectedly, for example after a power outage or suddenly being unplugged. This number may also increase if systems cut power a little too eagerly when going into hibernation mode. On some systems this number may therefore be higher than expected.

Total Programming Failures
Errors that happened while programming (writing) the NAND of the drive, usually a sign of worn or degraded NAND. This value going up advises caution, you should contact tech support if it rises swiftly within a short period of time.
Total Erase Failures
Numbers of failures at erasing of NAND of the drive. Much like Total Programming Failures, if this number increases rapidly within a short period of time, it is likely an indicator of degrading NAND.
Total Read Failures (uncorrectable)
This could be a sign of NAND failing but doesn’t have to be. If you see this value increasing swiftly within a short period of time, please contact tech support.
Average Erase Count
The average amount of erase cycles of a block of NAND on the drive since leaving the factory.
SATA CRC Error Count
If you see this number rising, there is need for investigation. In all likelihood, there is a problem with the way the drive is connected to the system. It could be either a faulty connector, a faulty cable or a problematic dock/3rd party adapter device.
In Warranty
States if the drive is within warranty (1) or not (0).
Host Writes (GB)
The amount of host writes to this drive in GB. This SSD had a total of 1705GB host writes.
Host Reads (GB)
The amount of host writes to this drive in GB. This SSD had a total of 1181GB host reads.
Total NAND Programming Count (pages)
The amount of programming cycles to the NAND of the drive’s pages.
Other drives may feature additional SMART attributes, such as:
Some drive models feature a temperature sensor. The measured temperature is usually displayed in degrees Celsius and may be hotter than the rated case temperature. The SMART temperature thus not necessarily reflects the case temperature.



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