SSD health: what SMART, TBW and the warranty tell you—and what they don’t

The question “How much health does my SSD have left?” sounds as though it calls for a simple number. In reality, it combines three separate questions: what the drive reports about its operation, how much written data its endurance rating specifies, and under what conditions the manufacturer provides support. SMART, TBW and the warranty are not interchangeable measurements: each addresses a different part of the issue.

SMART brings together diagnostic information that the drive exposes through attributes or log data. TBW (terabytes written) is an endurance specification expressed as a cumulative amount of data written. A warranty is a commitment subject to conditions; it may include a time period, a write limit or other requirements. None of these, by itself, is an exact prediction of when a drive will fail.

Keep these questions separate even when an application puts them together in a single “health” panel. SMART describes information reported by the drive; TBW helps explain an endurance specification; and the warranty defines possible coverage. A favorable-looking result in one area does not automatically settle the others. For example, warranty coverage does not replace diagnostic readings, and a reading with no warnings does not establish the terms of a contract.

On NVMe drives, the handling and logging of health and error information use device capabilities and log pages defined for the standard. The nvme-cli command-line utility lets users interact with NVMe drives and query management information. That does not mean every program translates the data in the same way, or that an attribute name guarantees an identical definition across manufacturers, models and interfaces.

An application may display data as fields, codes or a summarized percentage. That percentage is the tool’s interpretation; to understand it, you need to know which parameter it used and how it calculated the result. A health value displayed by an application is not automatically a probability of failure or a countdown. Keep the original values and check which drive, attribute and rule underpin the presentation.

The difference between a reading and its presentation matters especially when comparing programs. One tool may show a field under a readable name or summarize it on a scale, while another exposes the raw value. A visual discrepancy does not necessarily mean that the drive has changed state: first find out whether both tools are reading the same data and applying the same interpretation. Without knowing that rule, a percentage alone offers little context for deciding what the exact reading means for that device. It can also be useful to note the tool and version so that you can repeat the query under similar conditions later. That way, you compare the data, not merely the appearance of two different interfaces. A trend can add context, but it does not turn a reading into a prediction.

TBW expresses an amount of writing associated with the endurance specified for a drive. It is useful when comparing products in a particular capacity and product family, provided the figures are defined under equivalent conditions. It is not an expiry date: reaching the figure does not necessarily mean that the drive will stop working at that point, and remaining below it does not guarantee that the drive will never fail.

It is also important to distinguish the rated endurance from the total writes reported by a tool. The counter may reflect accumulated writes according to the drive’s definition and granularity; it is not necessarily identical to the data an application records as operating-system writes. Write amplification, cache use and the drive’s internal tasks make a direct comparison between computer activity and the SSD counter more complicated.

This explains why an observed number may not match an estimate based on the files a user believes they have saved. The operating system, drive and tool do not necessarily count exactly the same things, or use the same granularity. That does not mean one reading must be wrong; before comparing it with an external figure, find out what each counter represents. Avoid turning differences between figures into a conclusion about wear until you have checked their definitions and units.

A warranty answers a contractual question: what coverage the manufacturer offers and under what conditions. In some product ranges, the limit may be linked to a time period or a written-data volume, depending on the terms that apply to the product. Samsung’s warranty page, for example, separates coverage information from documentation and specification sheets for individual SSDs. Do not assume that the terms for one model also apply to another model or another region.

An SSD that is still covered can have a problem that deserves attention; an out-of-warranty drive can continue to work correctly. Conversely, being below the TBW limit does not prove that a fault will not occur. Coverage does not certify the drive’s condition, and the counter alone does not determine whether a claim is valid. For the latter, the applicable terms, proof of purchase, product identification and the manufacturer’s process all matter.

Before contacting support, gather the model and part number, region of purchase, available purchase date or proof, and a screenshot or export of diagnostic data. Consult the drive documentation and local warranty terms. If errors, interruptions or warnings appear, prioritize backing up important data: pursuing coverage and protecting files are related but separate tasks. Having these details ready also helps you explain the issue precisely; it does not presume that the manufacturer will accept or reject a claim. The outcome depends on the relevant terms and process.

A useful investigation begins by identifying the drive and obtaining a repeatable reading. Note whether it is NVMe or SATA, the manufacturer, model, capacity and firmware version shown by the system. Use a compatible tool and record its name and version; then compare the result with the manufacturer’s diagnostic documentation. Samsung maintains a document repository for its SSDs, but the relevant documentation must match the specific product.

Accurate identification prevents you from applying information from one product to another that merely looks similar. Manufacturer, product family and capacity are useful references, but you may also need to confirm the part number. Once you have gathered these details, consult the document associated with the drive rather than a general description that may not explain that model’s fields. This helps you interpret a reading without assuming all SSDs use identical attributes or limits.

Next, interpret the fields separately. Distinguish warning and error indicators from usage counters; check units, raw values and any derived percentage. If two programs disagree, do not automatically choose the more reassuring or more alarming result: they may display data using different scales or rules. Find out what information each reads and where its interpretation comes from. Understanding the source of the difference is more useful than averaging the results or selecting one without checking it.

A short checklist helps prevent hasty conclusions:

• Confirm the model, capacity, interface and firmware.
• Save the complete reading, not just the prominent percentage.
• Consult the manufacturer’s guide for the relevant fields.
• Check for warnings or errors, and whether they reappear in later readings.
• Compare the write counter with the specification for the same model and capacity.
• Back up data before investigating problems that could affect it.

This process does not replace a technical diagnosis if the drive becomes inaccessible or reports persistent errors. It helps you ask better questions and communicate verifiable information; it does not certify that the SSD is defect-free. Saving the complete reading and product references makes it easier to explain what you observed and in what context, without claiming that an indicator means more than it does. If results change between checks, noting when you obtained them helps distinguish separate readings; that comparison still does not guarantee future operation. Diagnostic data provides context but does not replace a backup of important files. This avoids relying on a single interpretation while you investigate. It is a precaution for your data, not a conclusion about the cause of a problem. Prioritize preserving accessible information over chasing a perfect number.

If tools disagree

First check whether they show the same field, unit and type of value. Then consult the documentation for each tool or for the manufacturer. If you still cannot reconcile the readings, keep both along with their versions and describe the difference when asking for help; do not present an interpretation as certain when the calculation rule is unclear. A discrepancy is a reason to verify, not in itself a diagnosis of failure.

A reasonable conclusion comes from several signals considered in context: an explicit device warning deserves attention; a write counter should be compared with the relevant specification; and warranty eligibility must be checked against the applicable terms. If symptoms appear or important data is at risk, backing it up is prudent even before you determine the cause.

What you cannot infer from a single number is just as important. A high percentage does not promise a particular remaining lifespan. TBW is not the precise moment of failure. A reading without errors does not rule out every possible failure. And although a warranty may offer a route to support, it is not a technical assessment of the drive’s current condition.

In short, read SMART as telemetry, TBW as an endurance specification, and the warranty as a coverage condition. Identify the drive precisely, consult the relevant documentation and keep a backup of valuable data. That combination is more useful than turning any isolated indicator into a verdict about how much time the SSD has left.