What is SSD TBW and How to Check Your SSD's TBW

Introduction

SSDs are gradually replacing HDDs. They are as quiet as a mouse, much faster, and less prone to failure. But they are more expensive per unit of storage, which is why some consumers hesitate to pay a premium for them.

Drive makers grade their drives based on three main attributes called TBW, Drive Writes Per Day (DWPD), and drive capacity. These reflect the durability of an SSD. Before you buy, you should also check the TBW of your SSD. But if you don't know what SSD TBW is or how to check it, you've come to the right place. This article will delve into everything you need to know about SSD TBW. Let's get started!

What is SSD TBW? TBW, which stands for Terabytes Written, is an important metric for Solid State Drives (SSDs). It represents the total amount of data that an SSD can write throughout its entire lifespan. This value is usually based on the manufacturer's durability and reliability tests and indicates the maximum amount of writing an SSD can withstand before reaching a certain level of degradation. TBW is typically calculated based on the endurance rating of each flash memory cell and the total storage capacity of the SSD. Since SSDs utilize flash technology, their storage cells have a limited number of write cycles. Once this limit is exceeded, the performance may degrade, eventually leading to failure. Knowing an SSD's TBW helps users estimate its lifespan and choose the appropriate SSD for their workload. Manufacturers generally provide TBW values in their product specifications and offer warranties that guarantee proper operation within the specified TBW range.

TBW (Terabytes Written) refers to the amount of terabytes that have been written, which is a statistical value, usually measured in terabytes, provided for storage devices. It tells you how many terabytes of data you can write to a hard drive before its internal storage units begin to degrade, increasing the likelihood of data loss and drive failure within the warranty period.

For example, if an SSD has a TBW of 350, you can write 350 terabytes of data to it before it needs to be replaced – roughly the equivalent of 75 to 150 TBW for most SSDs.

When this number is reached, it is recommended to replace the drive, as the data on it might not be as safe as it used to be. TBW is evenly distributed throughout the entire warranty period of the HDD, which is usually specified in single-digit years, commonly 3 or 5 years. Thus, the TBW of different HDDs can vary from just 30TB to several hundred.

Whether you move that much data over a few weeks during a peak period or spread out over several years, the warranty should cover moving that much data over that time.

Why Does TBW Matter?

Given that SSDs have a limited lifespan, the TBW rating is very important. SSDs use flash memory cells to store information. Reading data from these cells does not affect them, but erasing and writing to them causes them to degrade over time. Eventually, the flash memory cells will degrade to the point of becoming unusable. Thus, the TBW tells you how much information you can store before the memory cells fail.

When making a purchasing decision, TBW is an important factor to consider, as manufacturers are constantly looking to drive down costs while increasing the productivity and capacity of their drives, making them more affordable. For instance, if you're choosing between two drives with comparable read/write speeds, TBW should be the primary attribute you look at.

Larger drives with more NAND flash cells to write to have higher TBW ratings. For example, a common 500GB SSD might have a TBW rating of around 300, while a 1TB SSD typically has a TBW of 600.

Still, buying a drive with a high TBW rating ensures your drive will last longer than one with a much lower TBW. Frequent and varied backups, along with upgrading or replacing your drive before the warranty expires, should keep your data safe and your computer running swiftly for years to come.

How to Check the TBW of an SSD

Now that you know what TBW is and why it's important, you might be wondering how to check the TBW of an SSD or how to check it when buying one. Unfortunately, there's no way to manually check the TBW of an SSD, so you'll need a third-party tool to check the TBW of your SSD. If you're looking for such a tool, CrystalDiskInfo would be your best bet.

CrystalDiskInfo is a handy utility that tells you almost everything you'd want to know about the health and potential failure of your hard drive, using the S.M.A.R.T. (Self-Monitoring, Analysis, and Reporting Technology) method, which is built into most SSDs found in modern systems.

This includes information such as the current drive temperature, the number of failed read or write attempts, the drive's operating time, how often it's been started and stopped, and more. With this tool, you can easily check an SSD's TBW.

To check the TBW of your SSD using CrystalDiskInfo, follow these steps:

Step 1: Download and install CrystalDiskInfo on your computer, then launch it.

Step 2: Click on the Start button to launch the scan and wait for a few minutes for the results to appear. Now, select the name of your SSD from the top; for instance, if your local disk C:/ is your SSD, click on it.

Step 3: Here, on the left side of the screen, you'll see a value next to “Host Writes Total.” This is your SSD's TBW in terabytes.

Note: With CrystalDiskInfo, you can compare the used TBW with the one specified by the manufacturer. You can also check the drive's health, temperature, and more.

How many gigabytes do you typically write to a hard drive per day?

While the amount of HDD writes that any given person does in a day will vary, a typical office worker averages between 10 and 35 GB per day. At that rate, it would take them over five years to reach an SSD's TBW limit of 70 TB.

A typical TBW for a 250 GB SSD ranges from 60 to 150 TBW, meaning that to exceed the promised 70 TBW, a user would have to write an average of 190 GB of data every day for a year.

What happens when an SSD reaches its TBW limit?

Many people believe that once they exceed the TBW limit, their SSD will die. They think that once the TBW is full, the SSD is no good to them. This is not correct. Even after you use up your TBW quota, the SSD will still retain data, which you can access at any time. However, the writing function will no longer be available, and your SSD warranty will become void (if it wasn't already).

This measure, for storage devices, indicates how much data a hard drive can hold before its memory cells degrade. Once this threshold is reached, the risk of data loss or disk failure increases.

In addition, specifications like Mean Time Between Failures (MTBF) and Total Bytes Written (TBW) are estimates of the finite number of times cells can be written.

However, it's not uncommon to encounter SSDs that exceed these limits. People who have been using SSDs for a long time often exceed these limits. In very rare cases, an SSD might stop writing before it reaches the limit, or even stop working altogether. But this takes years to happen. There are people who have been using SSDs for 5 to 10 years without any issues.

Conclusions

Solid State Drives make your system run faster, and you can only fully grasp their excellent performance once you've used them in your system. They come with a TBW (Terabytes Written), which defines the writing limit of an SSD – an important factor to consider when purchasing or learning about the lifespan of an SSD. We hope this article has given you a comprehensive understanding of SSD TBW. Additionally, we recommend using CrystalDiskInfo to check your SSD's TBW, as it is a comprehensive platform.