What about SSDs and their lifespan? How often can a modern SSD be overwritten before its lifespan ends?

The lifespan of a solid-state drive (SSD) is determined by the number of write cycles the drive’s flash memory can withstand before it becomes unreliable. The number of write cycles depends on the type of flash memory used in the drive, but on average most modern SSDs are designed for 3,000 to 100,000 write cycles.

However, this figure can vary significantly depending on the quality of the flash memory and controller used in the drive, as well as how the drive is used and configured. Some SSDs can withstand more than 200,000 write cycles, while others may fail after only a few thousand cycles.

To extend the life of an SSD, manufacturers use wear-leveling algorithms that distribute data evenly across all cells of the controller. This helps ensure that all cells wear out more evenly over time. It is also possible to check the current status of an SSD with the SMART analysis tool, which indicates the remaining lifespan of an SSD.

Another important aspect is the “Terabytes Written” value (TBW), which indicates how much data can be written to the SSD over its lifetime. A typical TBW value for a 250 GB SSD lies between 60 and 150 terabytes. This means that a user would have to write about 190 GB every day for an entire year to reach the TBW limit.

In summary, SSDs offer several advantages over HDDs, such as higher speed, lower power consumption, and greater durability. However, their lifespan is limited by the number of write cycles that the drive’s flash memory can endure before becoming unreliable. To extend the life of an SSD, it is important to use wear-limiting algorithms and check the current status of the SSD with the SMART analysis tool. It is also important to consider the TBW value when choosing an SSD.

For this reason, it is insignificant in terms of shortening the lifespan if a user securely erases an SSD from time to time with iShredder and, for example, the 4-round Protectstar ASDA method.


***Update (regarding TBW calculation and write amplification): March 28, 2025***:
Some readers pointed out that at first glance it may seem contradictory if a 250 GB SSD, for example, is rated for “only” 125 TBW even though flash cells according to the data sheet can sometimes withstand 3,000 or more write cycles.

This is because the TBW value (Terabytes Written) is not simply “(capacity) × (number of P/E cycles).” In their TBW figures, manufacturers take into account, among other things, the so-called Write Amplification Factor (WAF), which arises from processes such as wear leveling and garbage collection. This means that more internal writes can occur than the amount of user data actually written. In addition, a certain percentage of over-provisioning is often included.

As a result, an SSD may indeed be able to handle thousands of write cycles per memory cell according to the data sheet, but still end up with a TBW rating that appears lower to the user. The TBW figure is therefore more of a warranty value than a direct indicator of the exact number of full-capacity overwrites possible from “full capacity × number of cycles.”

In practice, many SSDs often last significantly longer than their TBW specification suggests. Anyone who wants to play it safe should choose a higher TBW value and avoid unnecessary write load. Even so, the following still applies: if a secure deletion method is used occasionally (such as the 4-round Protectstar ASDA method with iShredder), the impact on SSD lifespan is low in most cases—as long as you do not run it in a continuous loop.
 

Further information:
iShredder: https://www.protectstar.com/de/products/ishredder
Protectstar ASDA algorithm: https://www.protectstar.com/de/secure-erase
Blog article: https://www.protectstar.com/de/blog/how-long-your-ssd-really-lasts-everything-about-write-cycles