Definition: TBW (Total Bytes Written) is the manufacturer’s endurance rating for an SSD — the total amount of data that can be written to the drive over its lifetime before NAND flash cells begin to fail. A 1TB NVMe SSD typically has a TBW rating of 300–600TB. Remaining TBW is the most reliable indicator of an SSD’s remaining useful life when buying or selling used drives.
Why it matters when selling or buying used SSDs
Unlike mechanical hard drives where age and hours of use matter most, SSDs wear out based on how much data has been written — not how long they’ve been running. A 5-year-old SSD used lightly may have far more life left than a 2-year-old SSD used intensively for video editing.
At BreakFixNow, when we assess a used SSD for trade-in, we check TBW remaining using CrystalDiskInfo (Windows) or smartmontools (Linux). An SSD at 90%+ remaining TBW is as good as new. Below 50% the offer reflects the reduced remaining life.
How to check your SSD’s TBW health
- Windows: Download CrystalDiskInfo (free). Open it and look at “Total Host Writes” and the health percentage. A yellow or red health indicator means the drive is approaching end of life.
- Samsung SSDs: Samsung Magician software shows detailed health and remaining TBW.
- BIOS/UEFI: Some boards show basic drive health in the storage section.
Typical TBW ratings by drive tier
- Budget NVMe 1TB (e.g. Kingston NV3): ~200TB TBW
- Mid-range NVMe 1TB (e.g. WD Blue SN580): ~300TB TBW
- Performance NVMe 1TB (e.g. Samsung 990 Pro): ~600TB TBW
- SATA SSD 1TB (e.g. Samsung 870 EVO): ~600TB TBW
Common mistakes
- Ignoring TBW when buying used SSDs. A cheap used SSD with 80% TBW consumed is a poor buy regardless of price. Always check health before purchasing.
- Confusing TBW with read endurance. TBW only measures write endurance. SSDs can read data indefinitely — writes cause wear.
- Thinking TBW = guaranteed failure point. Drives often survive beyond their rated TBW. The rating is a conservative manufacturer guarantee, not a cliff edge.
Related terms
- NVMe vs SATA SSD — both have TBW ratings
- Desktop PC Upgrade Singapore — SSD upgrade service at BreakFixNow
Upgrading your desktop storage?
BreakFixNow installs NVMe and SATA SSDs with full OS and data migration. Labour from $50. Walk in — no appointment needed.
BreakFixNow installs NVMe and SATA SSDs with full OS and data migration. Labour from $50. Walk in — no appointment needed.