SSD Endurance (TBW) Explained: How Long Will Your SSD Last?

Every SSD has a limited number of times its flash memory can be written to before cells start to wear out. That fact makes a lot of buyers nervous, especially when comparing a cheaper QLC drive with a premium TLC one. The reality is reassuring: for almost everyone, an SSD's endurance rating is so far beyond what they'll actually use that the drive will be obsolete long before it wears out. But there are workloads where it does matter, and knowing how to read the numbers helps you buy the right drive.

Why SSDs wear out at all

SSDs store data by trapping electrical charge inside tiny cells of NAND flash. Every time a cell is erased and rewritten, the insulating layer that holds the charge degrades a little. After enough cycles, the cell can no longer hold its charge reliably and is retired.

The drive's controller works hard to delay that point. It spreads writes evenly across all cells (called wear levelling), keeps spare cells in reserve to replace worn ones, and uses error correction to recover data from cells that are starting to weaken. Endurance ratings take all of that into account.

What TBW means

TBW stands for terabytes written. It's the total amount of data the manufacturer guarantees you can write to the drive over its warranty period. A drive rated at 600 TBW is covered until you've written 600 terabytes to it, or until the warranty period ends, whichever comes first.

Ratings scale with capacity, because a bigger drive has more cells to spread writes across. Within the same product line, the 2TB model is typically rated for about twice the TBW of the 1TB model. As a rough guide for consumer drives:

• Mainstream TLC drives: often around 600 TBW per terabyte of capacity.
• Budget and QLC drives: often somewhere around 200 to 400 TBW per terabyte.

Always check the exact figure on the manufacturer's spec sheet, usually listed under "endurance" or "warranty".

What DWPD means

You'll sometimes see endurance given as DWPD, short for drive writes per day. It tells you how many times you could fill the entire drive every single day for the length of the warranty. It's more common on workstation and data-centre drives, but you can convert any TBW rating into DWPD:

For example, a 1TB drive rated at 600 TBW with a 5-year warranty works out to 600 ÷ (1 × 5 × 365), or about 0.33 DWPD. That means you could write a third of the drive's capacity, about 330GB, every day for five years.

How much do you actually write?

This is where the fear usually disappears. A typical home or gaming PC writes somewhere around 10 to 30GB per day, including Windows updates, browser cache, game patches and everyday files.

At 30GB a day, you write about 11TB a year. On a 600 TBW drive, that's more than 50 years of use. Even a 200 TBW budget drive would last well over 15 years at that rate.

Heavy gamers who regularly install and uninstall large titles might write more, but even 100GB a day comes to about 36TB a year, still giving a 600 TBW drive more than 16 years.

TBW is a warranty limit, not a countdown to failure

Reaching your TBW rating doesn't mean the drive stops working. It means the manufacturer no longer guarantees it. Independent endurance tests over the years have repeatedly shown consumer SSDs continuing to work well past their rated TBW, sometimes by a large margin.

In practice, SSDs that fail early usually fail for other reasons: a controller fault, a firmware bug or a power problem. Those failures can happen at any point and have nothing to do with how much you've written. That's why backups matter far more than endurance ratings for keeping your data safe.

When endurance does matter

A few workloads write far more than normal and can genuinely use up a drive's endurance in a few years:

• Video editing scratch and cache drives, especially with high-bitrate 4K or 8K footage.
• Virtual machines and local servers that run all day.
• Databases, development builds and large compile jobs that constantly rewrite files.
• Security camera recording or always-on download drives.

For these, choose a TLC drive with a high TBW rating, buy more capacity than you need (a bigger drive has more endurance and its cache stays effective for longer), and keep an eye on its health. For a general-purpose system or a game library, endurance shouldn't be the deciding factor.

How to check your SSD's health

You can see exactly how much has been written to your drive and how much of its rated life is used:

1. CrystalDiskInfo (free, Windows) shows Health Status as a percentage and Total Host Writes in gigabytes or terabytes. Download it from the official crystalmark.info website.
2. Your drive maker's tool shows the same information with a simpler interface: Samsung Magician, WD Dashboard, Crucial Storage Executive and Kingston SSD Manager all display health and total data written.
3. For NVMe drives, look for Percentage Used. It starts at 0% and counts up as the drive approaches its rated endurance. It can go past 100%, which simply means the drive has exceeded its rating.

Compare Total Host Writes against the TBW rating on your drive's spec sheet to see how much of its warranty endurance you've used.

Buying advice in one paragraph

For a boot drive, a gaming drive or a general-purpose PC, buy based on price, speed and capacity, and don't worry about TBW. Any mainstream drive will outlast its usefulness. For heavy write workloads, choose TLC over QLC, pick the largest capacity you can afford and compare TBW ratings directly. Whatever you buy, keep a backup of anything you can't afford to lose.

The short version

TBW is the total amount of data your SSD is guaranteed to handle. Most people write so little that even a budget drive would take a decade or more to reach its rating, and drives usually keep working past it anyway. Endurance only becomes a real consideration for heavy, constant-write work like video editing or virtual machines. Check your drive's health in CrystalDiskInfo or your maker's tool, and keep backups either way.