What Is Internal SSD TBW? An Easy Guide to Understanding Durability Ratings!

TBW stands for Terabytes Written, which simply means how much total data an Internal SSD can write in its lifetime without affecting stable operation.
For example: If a 2TB Internal SSD is rated at 2,000TBW, that means it can handle 2,000 terabytes of data written over its lifetime. Under normal use, it’s actually really hard to reach that limit! The higher the TBW, the more durable the Internal SSD. This depends on the quality of the NAND flash inside, for example, TLC and QLC types have different endurance levels. For most users like gamers or office workers, it’s nearly impossible to reach the TBW limit during normal use.
However, the following types of users should pay special attention to TBW:

• Content creators who frequently edit videos, photos, or back up large files.
• Server or NAS users who constantly write data.
• Heavy users who often install/delete games or transfer large amounts of data.

Each write and erase cycle gradually wears out the NAND cells, and drives with lower TBW ratings may reach their endurance limits sooner.



  TBW is determined based on: (Capacity in GB× NAND durability) ÷ Write amplification factor (WAF)

• Capacity: Larger drives have more NAND cells, spreading out writes and extending lifespan.
• NAND durability: Different flash types (SLC, MLC, TLC, QLC) have different write endurance per cell.
• Write amplification factor (WAF): Indicates how much additional work the Internal SSD must do to store data. A lower WAF = higher endurance.

For instance, a 1TB (1,000 GB) TLC SSD with 1,000 program/erase cycles (NAND durability) and a WAF of 1.5 might have a TBW of around 666TB.


    In short, TBW shows how much total data an Internal SSD can handle over its lifetime, a higher TBW means better endurance. While casual users rarely reach this limit, those working with large files or constant backups should consider TBW carefully. When choosing your next Internal SSD, remember that speed delivers quick performance, but endurance ensures long-term reliability.

That’s all for today’s quick tech tip!
If you’d like to learn more Internal SSD tricks and tips, stay tuned, see you next time!