Which SMART attribute tracks NAND wear and endurance consumption?

• A. Temperature_Celsius (ID 194)
• B. Wear_Leveling_Count (SSDs)
• C. Power_On_Hours (ID 9)
• D. UDMA_CRC_Error_Count (ID 199)

Answer: (B)

NAND flash wears out with each program/erase cycle, and wear leveling is used to spread writes evenly to extend the drive’s life. The SMART attribute Wear_Leveling_Count specifically tracks how much wear the flash has incurred and how much endurance has been consumed. As the drive experiences more write activity, this count increases (or the corresponding life percentage decreases, depending on the vendor’s reporting). This makes it the best indicator of endurance and wear.

The other options don’t measure wear: Temperature_Celsius reflects heat, Power_On_Hours shows how long the device has powered on, and UDMA_CRC_Error_Count logs transmission errors on the data path. Each of these provides different information and not the wear or endurance of the NAND.