Writing Cycle and Endurance
Whenever data is written to a flash memory cell, it undergoes a slight degradation. Over time, this degradation can reduce the ability of cells to store data reliably. The write cycle refers to the number of times data can be written and deleted on an SSD before its cells begin to lose integrity.
- Endurance: A metric that measures how many write cycles an SSD can handle before it degrades significantly. SLC has the highest endurance, followed by MLC, TLC, and QLC.
Data Retention Test Results on SSDs under Different Conditions
Research conducted by PCWorld tested the data retention capabilities of SSDs with various types of flash memory under different temperature conditions. This trial was conducted to understand the extent to which SSDs can retain data without a power supply.
Testing Conditions
- Room Temperature (25°C): SSDs are tested under stable room temperature conditions.
- High Temperature (35°C): SSDs are tested under higher temperature conditions to simulate less-than-ideal storage scenarios.
- Extreme Temperature (45°C): SSDs are tested under extreme temperature conditions to measure the limits of data retention capabilities.
Test Results
- SLC (Single-Level Cell): At room temperature, SLC is capable of retaining data for up to 10 years. At high temperatures, data retention decreases to about 5-7 years and at extreme temperatures to 2-3 years.
- MLC (Multi-Level Cell): At room temperature, MLC can retain data for up to 5-7 years. At high temperatures, data retention decreases to about 3-5 years and at extreme temperatures to 1-2 years.
- TLC (Triple-Level Cell): At room temperature, TLC can retain data for up to 3-5 years. At high temperatures, data retention decreases to about 2-3 years and at extreme temperatures to 6-12 months.
- QLC (Quad-Level Cell): At room temperature, QLC can retain data for up to 2-3 years. At high temperatures, data retention decreases to about 1-2 years, and at extreme temperatures to less than 6 months.
PCWorld’s research shows that the data retention capabilities of SSDs are greatly influenced by the type of flash memory and storage conditions. SSDs with SLC flash memory have the best data retention, while QLC has the worst data retention. High temperatures significantly accelerate data degradation on all types of SSDs. Therefore, for long-term data storage, it is important to store the SSD at a stable room temperature and choose an SSD with a more reliable type of flash memory such as SLC or MLC.
User Experience
According to discussions conducted by users and experts on Quora, many experiences and comments talk about data retention on SSDs from a practical point of view.
User Experience
- Professional Users: Many professional users who work in IT and data storage report that they rarely rely on SSDs for long-term data storage without power. They are more likely to use HDDs or other more stable storage solutions for data archiving.
- Consumer Users: Home users are usually more worried about data loss in the short term. They often rely on SSDs for speed and day-to-day performance, but still back up to other storage media at regular intervals.
Real Case Studies of Different Types of SSDs
- SLC SSDs: One user reported that SSDs with SLC flash memory used in industrial environments were able to retain data for more than 5 years without a power supply, even in quite volatile temperature conditions.
- MLC SSDs: Other users have reported that MLC SSDs used in data center servers are capable of retaining data for 3-4 years without a power supply, noting that the SSDs are stored under controlled temperature conditions.
- TLC and QLC SSDs: Many users report that SSDs with TLC and QLC flash memory are more susceptible to data loss in less than 2 years without a power supply, especially if stored in high-temperature conditions or unstable environments.
Discussions on Quora confirm that flash memory type and storage conditions are critical factors in data retention on SSDs. SLC and MLC provide the best performance for data retention, while TLC and QLC are more suitable for high-capacity, low-cost uses, but not for long-term data storage without a power supply. Users should consider the type of flash memory used in their SSD and make sure to store the SSD in ideal environmental conditions to maximize data lifespan.