SanDisk uSSD 5000 - Manual (Page 9)

SanDisk uSSD 5000 Product Manual
© 2007 SanDisk® Corporation 8 August 2007
2.5 System Reliability
Table 5: Reliability
Specification Parameters
Data Reliability Error detection / error correction based on
BCH algorithm
Data integrity after power loss Data is guaranteed after power loss
Bad blocks Transparent bad block management
Wear-leveling Dynamic and Static Wear-leveling
2.5.1 MTTF
The reliability figure of merit most often used for electronic equipment is Mean
Time To Failure (MTTF). SanDisk estimates MTTF using a prediction
methodology based on reliability data for the individual components in
SanDisk products.
Component data comes from several sources: device life tests, failure analysis
of earlier equipment, device physics, and field returns.
SanDisk uses following methods to predict reliability:
• Telcordia Special Report SR-332, Reliability Prediction Procedure for
Electronic Equipment (RPP).
• British Telecom Industry HRD5, Handbook of Reliability Data for
Electronic Components used in Telecommunication System.
Table 6 summarizes the MTTF prediction results for various uSSD
configurations. The analysis was performed using a RAM Commander™ failure
rate prediction.
• Failure Rate: The total number of failures within an item population,
divided by the total number of life units expended by that population,
during a particular measurement interval under stated condition.
• Mean Time To Failures (MTTF): A basic measure of reliability for
repairable items: The mean number of life units during which all parts of
the item perform within their specified limits, during a particular
measurement interval under stated conditions.
Table 6: uSSD MTTF
Product Condition MTTF (Hours)
1GB, 2GB, 4GB Telcordia SR-332, GB, 25°C 4M
8GB Telcordia SR-332, GB, 25°C 3M