Frequently Asked Questions

CFexpress cards and SSDs are essential to modern photography and videography. We trust them to capture, preserve, and transport work that may be difficult—or impossible—to recreate.

Yet unlike cameras and lenses, storage devices provide few obvious indications of their internal condition. A card may continue to record photographs, transfer files, and appear to function normally while its controller is reporting changes in wear, reserve capacity, temperature, or reliability.

Understanding those measurements offers another way to evaluate the equipment entrusted with our work.

Modern CFexpress cards and SSDs use NAND flash memory, managed by sophisticated electronic controllers.

Flash memory has a finite endurance. Repeated programming and erasing gradually wear its memory cells, while controllers must continually manage data placement, error correction, and the allocation of reserve capacity.

Failures can also result from electronic faults, firmware problems, thermal stress, physical damage, or other causes unrelated to ordinary flash wear.

Not every failure develops gradually, and not every problem produces a recognizable warning.

Yes.

Some failures occur abruptly, with little or no advance indication. Others may be preceded by changes in controller-reported information, such as increasing media errors, declining reserve capacity, or unusual thermal behavior.

The difficulty is that these measurements are not ordinarily visible during everyday photographic work.

Even when they are available, interpreting an isolated reading can be challenging. A measurement may be entirely normal, represent an isolated event, or form part of a developing pattern.

This is one reason why examining a device’s operating history can be more informative than relying on a single inspection.

Not necessarily.

Successful recording and file transfers establish that a device is performing those operations at that moment. They do not, by themselves, establish the condition of its flash memory, controller, or remaining endurance.

Modern storage devices are designed to manage wear and correct certain errors internally, often without interrupting normal operation.

That resilience is valuable, but it also means that ordinary use may reveal relatively little about the processes occurring beneath the surface.

A device can appear to function normally while reporting conditions that deserve closer attention. Conversely, a device with substantial operating history may remain in reassuring condition.

The distinction matters: successful operation is useful evidence, but it isn’t a complete assessment of device health.

Surprisingly little, particularly when it comes to CFexpress cards.

To our knowledge, there are no publicly available, large-scale studies establishing the failure rates of CFexpress cards used in photography and videography. Without such data, it is difficult to make meaningful statements about how frequently these cards fail, how their reliability changes with age, or whether particular failure mechanisms are more prevalent than others.

For SSDs, some useful information is available from Backblaze, a cloud storage company that publishes statistics on the reliability of drives operating in its data centers.

Two particularly informative reports are:

• The SSD Edition: 2023 Mid-Year Drive Stats Review
• Are SSDs Really More Reliable Than Hard Drives?

These studies provide valuable insight into storage reliability, but their applicability to consumer SSDs and CFexpress cards is limited. The drives studied operated in a managed commercial environment, with particular workloads, usage patterns, and operating conditions. Backblaze’s SSD reports also primarily concern drives used as boot devices rather than the high-performance removable media employed by photographers and videographers.

Despite their different shapes and intended uses, modern CFexpress Type B cards and NVMe SSDs share much of the same underlying technology.

Both use NAND flash memory to store information electronically, without the moving parts found in traditional hard drives. They also contain sophisticated controllers responsible for managing how information is written, retrieved, protected, and maintained.

Unlike conventional magnetic storage, NAND flash memory cannot simply overwrite existing information in place. Data is written in units called pages, while previously written memory must be erased in larger units called blocks before those cells can be reused.

The controller manages these operations behind the scenes. It distributes writes across available memory, corrects certain errors, manages defective blocks, and maintains reserve capacity to support continued operation.

Most of this activity is invisible to the user. A photograph appears as a file on a card, but beneath that simple interaction lies a complex system continually managing the physical memory that stores it.

If NAND flash memory is where information is stored, the controller is the intelligence responsible for managing it.

A modern flash controller does far more than read and write files. It determines where information is physically stored, distributes writes across memory cells, manages the replacement of defective blocks, corrects errors, and coordinates the many internal operations necessary to keep the device functioning reliably.

It also manages performance and responds to operating conditions. When temperatures rise, for example, the controller may reduce activity to limit further heating and protect the device.

The controller maintains internal records about many aspects of the device’s operation, including accumulated usage, estimated wear, reserve capacity, temperature, and certain reliability-related events.

These records provide a valuable perspective on the condition of the device—one that is not ordinarily available simply by examining the files stored on it.

The controller itself is also an important potential point of failure. Electronic faults, firmware problems, and failures in the controller’s management of flash memory can compromise a device even when its memory cells have not approached their expected endurance limits.

This is why understanding flash storage requires looking beyond the memory itself.

NVMe, short for Non-Volatile Memory Express, is a communication protocol developed for high-performance solid-state storage.

It defines how a computer communicates with a compatible storage controller, allowing commands, data, and management information to be exchanged efficiently.

CFexpress Type B cards and many modern SSDs use NVMe over a PCI Express connection. Although their physical forms and applications differ, they share an important common language.

Beyond reading and writing data, NVMe defines mechanisms through which a controller can report information about its operating condition.

One particularly useful source is the NVMe SMART / Health Information Log, which can include measurements and counters such as:

• Current temperature and certain thermal-exposure indicators
• Available spare capacity and its warning threshold
• Estimated endurance consumption
• Data read and written
• Power-on hours and power cycles
• Unsafe shutdowns
• Media and data-integrity errors
• Critical warnings reported by the controller

Some devices provide additional thermal-management information, while others may offer more limited reporting.

These measurements can help describe how a device has been used, what conditions it has experienced, and whether its controller has reported events deserving attention.

There are important limitations, however. NVMe provides a standardized framework for reporting information, but the availability, implementation, and interpretation of particular measurements can vary among devices and manufacturers.

Access also depends on the connection between the device and the computer. A reader or enclosure may permit normal file transfers while preventing access to the underlying NVMe management information.

Consequently, NVMe telemetry is a valuable source of evidence about device condition, but it is neither a complete account of everything occurring within the device nor a guarantee of future reliability.

Yes. NAND flash memory has a finite endurance.

Each time a memory block undergoes a program-and-erase cycle, the physical structures used to store electrical charge experience a small amount of wear. Over many cycles, the ability of individual cells to retain and reliably represent information can deteriorate.

This does not mean that a card becomes unreliable after a particular number of photographs or that its useful life can be determined simply by its age.

Modern flash controllers employ techniques such as wear leveling, error correction, and the management of reserve memory to extend useful life and maintain reliable operation.

The rate at which a device accumulates wear depends on many factors, including the type of NAND memory, the amount and pattern of data written, the controller’s management strategies, and the device’s design.

Flash endurance is therefore best understood as a characteristic that develops through use, rather than a fixed expiration date.

Flash storage devices typically include physical memory beyond the capacity made available to the user.

Some of this additional memory supports internal operations and provides replacement blocks when portions of the flash can no longer be used reliably.

As a device operates, its controller may retire problematic blocks and substitute reserve blocks to maintain the storage capacity and functionality presented to the computer.

Many NVMe devices report a measurement called Available Spare, which indicates the remaining available spare capacity according to the controller’s implementation.

A declining reserve-capacity measurement may deserve attention, particularly if it approaches a manufacturer-defined threshold or changes alongside other evidence of deterioration.

However, the reported percentage should not be interpreted as the percentage of unused storage space, nor does it necessarily represent a directly measurable fraction of physical reserve blocks.

It is a controller-reported indicator whose significance must be considered in context.

NVMe devices may report a measurement called Percentage Used, which represents the controller’s estimate of how much of the device’s expected endurance has been consumed.

Card Inspector Pro presents this concept as estimated wear.

The estimate is based on the manufacturer’s endurance model and the device’s accumulated usage. It is not a direct measurement of how many individual memory cells have failed.

Importantly, a reported value of 100% does not mean the device has failed or will immediately stop working. It indicates that the controller estimates the device has reached its specified endurance consumption.

A device may continue operating beyond that point, although its remaining endurance and reliability cannot be assumed.

Conversely, a low estimated-wear value does not guarantee that a device is free from defects or other potential failure mechanisms.

Estimated wear is useful evidence about a device’s operating life, but it is not a countdown clock to failure.

NAND flash memory is not perfectly error-free. Small errors can arise as memory cells wear, electrical characteristics change, or stored charge becomes more difficult to distinguish reliably.

Modern controllers use error-correcting techniques to detect and correct many of these errors before they affect the information returned to the computer.

This is an essential part of normal flash operation, not necessarily an indication that a device is failing.

Controllers also manage problematic memory blocks, moving data or retiring blocks when necessary.

NVMe devices can report certain errors that their internal correction mechanisms could not successfully resolve. These are distinct from the routine, corrected errors that may occur during normal operation.

A reported media or data-integrity error deserves attention, but its significance depends on the circumstances, whether it recurs, and what other evidence is available.

An isolated historical event and a developing pattern of errors do not necessarily tell the same story.

Temperature plays an important role in the operation of flash storage.

Writing, reading, and managing NAND flash memory generate heat, particularly during sustained high-speed activity. Modern CFexpress cards and SSDs are designed to operate within specified temperature ranges, but their thermal environments can vary considerably.

A CFexpress card recording high-bitrate video inside a camera, for example, may experience different thermal conditions from an SSD operating in a ventilated computer enclosure.

When temperatures become excessive, the controller may reduce performance through a process commonly called thermal throttling. This limits further heating and helps maintain operation within the device’s intended thermal limits.

Temperature can also affect the underlying flash memory. Elevated temperatures can accelerate certain physical degradation processes and influence the ability of memory cells to retain stored information. The effects depend on temperature, exposure duration, flash technology, and the device’s design and operating conditions.

Not every high-temperature reading indicates damage, however. Brief thermal excursions, sustained exposure, and repeated thermal-management activity may have different implications.

Some NVMe controllers report not only their current temperature, but also accumulated time spent above specified thermal thresholds or the frequency and duration of thermal-management interventions.

Such information can help distinguish an isolated temperature measurement from a broader history of thermal exposure.

Temperature is therefore more than a performance consideration. It is part of the operating context in which flash endurance, data integrity, and device reliability must be understood.

At the same time, thermal measurements alone cannot establish that a device has suffered damage or predict how long it will remain reliable.

Card Inspector Pro is a macOS application designed to help photographers, videographers, and Mac enthusiasts better understand the health, reliability, and operating history of compatible CFexpress cards and NVMe storage devices.

Modern flash storage controllers record a remarkable amount of information about their operation. Temperature, estimated wear, reserve capacity, media errors, unsafe shutdowns, and accumulated workload are among the measurements that may be available.

Card Inspector Pro brings this information together in an accessible interface, making it possible to examine both the current condition of a device and how its reported behavior has developed over time.

But the application goes beyond displaying measurements.

It evaluates the available evidence, considers the relationships among different indicators, and presents an assessment of device health and reliability in language intended to be understandable and useful.

The objective is not simply to provide more information. It is to help users make better sense of the information their storage devices already report.

Card Inspector Pro communicates with compatible storage devices through the management information made available by their NVMe controllers.

When a supported device is selected, the application retrieves available information about its identity, operating condition, accumulated usage, and reliability-related events.

The inspection is non-destructive. Card Inspector Pro does not need to write test files to the device, perform a destructive endurance test, or examine the contents of photographs, videos, and other user files.

Instead, it examines information maintained by the storage controller itself.

Each inspection provides a snapshot of the device’s reported condition at that moment. When successive inspections are available, Card Inspector Pro can also examine changes between observations.

This distinction is important. Card Inspector Pro does not continuously monitor a device while the application is closed. Its historical analysis is based on the inspections that have actually been recorded.

Conventional SMART utilities provide access to information reported by storage controllers, including temperature, estimated wear, reserve capacity, accumulated workload, and reliability-related events.

These measurements are valuable. But interpreting their significance can be considerably more complicated than simply determining whether an individual value falls within an acceptable range.

Card Inspector Pro was developed to address that challenge.

At its core is a sophisticated, evidence-based inference engine that integrates immediate controller warnings, current device condition, accumulated operational information, and longitudinal observations of device behavior.

Rather than evaluating measurements in isolation, the application examines their significance within the broader context of the device’s reported operation.

A media-error count, for example, may represent an isolated historical event, a recurring condition, or a developing pattern of deterioration. A temperature measurement may be unremarkable on its own but acquire greater significance when considered alongside sustained thermal exposure or repeated thermal-management activity.

Card Inspector Pro examines not only what a device is reporting, but also the character and direction of its behavior. Where sufficient historical evidence exists, it can distinguish conditions that are stable, continuing, or materially worsening, while recognizing when the available observations do not support a reliable conclusion.

These findings are integrated into an overall assessment that considers the device’s present state, operating trajectory, and whether identified concerns are bounded by the available evidence.

The result is more than a collection of technical measurements or a simple pass/fail indication. It is a reasoned assessment of device health and reliability, supported by the evidence available at the time of inspection.

Card Inspector Pro doesn’t simply show you what your storage device reports. It helps you understand what that information means.

Card Inspector Pro evaluates several aspects of device operation, including controller-reported warnings, data integrity, endurance and reserve capacity, thermal behavior, and operational history.

Its assessment considers both the present condition of the device and, where available, evidence from previous inspections.

An important part of this process is distinguishing a condition that merely exists from one that is developing, recurring, worsening, or remaining stable. The application examines these behaviors within their operational context, recognizing that individual measurements may acquire different significance when considered alongside other evidence.

The application also considers the quality and completeness of the available evidence. A conclusion supported by repeated observations may carry different significance from one based on a single inspection. Where the evidence is insufficient or inconclusive, Card Inspector Pro recognizes those limitations rather than assigning unwarranted certainty.

These considerations are integrated into an overall assessment that reflects the device’s reported condition, observed behavior, and the strength of the supporting evidence at the time of inspection.

The assessment is evidence-based rather than predictive. It does not calculate a probability of failure, estimate a remaining lifespan, or guarantee that a device will continue operating reliably.

Card Inspector Pro uses five assessment classifications to communicate the significance of the available evidence.

Excellent — The available evidence is reassuring, with sufficient historical observations to establish stability.

Healthy — The device’s reported condition is compatible with normal, reliable operation, although the available evidence does not establish the stronger longitudinal reassurance required for Excellent.

Observe — A condition, behavior, or unresolved uncertainty warrants attention, but material degradation has not been established.

Caution — The available evidence establishes a material concern about the device’s condition or behavior.

Critical — The available evidence establishes a serious adverse condition requiring prompt attention.

These classifications are not predictions of future failure. They describe what can reasonably be concluded from the information available at the time of inspection.

When the evidence is insufficient to support a meaningful assessment, Card Inspector Pro may instead report an indeterminate result. This is not a sixth health classification; it indicates that a defensible conclusion cannot be reached.

A single inspection provides valuable information about a device’s reported condition. But many important questions cannot be answered from one observation alone.

Has reserve capacity been declining, or has it remained unchanged? Did a media error occur recently, or has the count been stable across many inspections? Is an adverse condition recurring, becoming more frequent, or no longer evident?

These are questions about behavior over time.

Card Inspector Pro preserves successive inspections so that current measurements can be considered alongside earlier observations.

Its History features allow users to examine changes in wear, reserve capacity, temperature, reliability indicators, and workload.

Historical evidence also contributes to the application’s assessments. Repeated observations may establish reassuring stability, reveal a developing concern, or clarify the significance of an isolated event.

Importantly, an absence of observed change is not always sufficient to establish stability. The available history must provide an adequate basis for that conclusion.

This is one of the central principles behind Card Inspector Pro: understanding a device’s present condition often requires understanding how it arrived there.

Some storage manufacturers provide software designed to help customers maintain, manage, and evaluate their devices. These applications can be valuable, and Card Inspector Pro is not intended to replace their specialized functions.

Depending on the manufacturer and device, such software may support firmware updates, card sanitization or refresh operations, TRIM-related maintenance, performance testing, and health checks based on controller-reported information.

These capabilities serve important purposes. Firmware updates may address compatibility or operational issues, while maintenance operations may help restore performance under certain conditions. Manufacturer utilities may also provide useful assessments of remaining flash endurance or overall card health.

Card Inspector Pro takes a different approach.

Its primary purpose is not device maintenance, but a deeper understanding of device condition and behavior.

First, inspection is non-destructive. Card Inspector Pro retrieves available controller-reported information without writing test data, performing stress benchmarks, sanitizing the card, or modifying its stored contents. Its inspections are designed to have minimal impact on the device being examined.

Second, its assessment extends beyond a snapshot of current operation. Card Inspector Pro integrates controller warnings, device-health indicators, accumulated operating information, and observations from successive inspections. Its inference engine evaluates these sources together to distinguish reassuring conditions, material concerns, and changes in device behavior that deserve attention.

Third, history is an integral part of the assessment. Rather than simply preserving earlier measurements for reference, Card Inspector Pro uses available longitudinal evidence to examine stability, recurrence, and developing adverse behavior. This allows the application to consider not only a device’s present condition, but also its observed trajectory.

Finally, Card Inspector Pro presents its findings in language intended to make sophisticated storage-health information accessible without requiring specialized knowledge of NVMe or flash-memory engineering.

Manufacturer software and Card Inspector Pro can therefore serve complementary purposes. One may provide tools for maintaining or updating a device; the other provides an independent, evidence-based perspective on its reported condition and operating history.

The distinction is between maintaining a storage device and understanding its health, reliability, and behavior over time.

No. Card Inspector Pro cannot reliably predict when a storage device will fail, and it is not designed to provide a remaining-life estimate.

Some failures occur suddenly because of electronic faults, firmware defects, physical damage, or other events that may not produce recognizable warning signs in the available telemetry.

Other problems may be accompanied by changes in controller-reported information, such as increasing media errors, declining reserve capacity, or persistent adverse operating conditions.

Card Inspector Pro helps users recognize and interpret such evidence when it is available.

But the absence of concerning measurements does not guarantee that a device will remain reliable, just as the presence of an abnormal measurement does not necessarily mean failure is imminent.

Card Inspector Pro is an aid to understanding device condition, not a substitute for appropriate backups, careful handling, or established data-protection practices.

Its value lies in making more of the available evidence understandable—not in claiming to know the future.

Card Inspector Pro is available for a single, one-time purchase. There are no recurring subscription fees.

Your purchase includes two licenses for Card Inspector Pro Version 1, allowing you to use the application on two compatible Macs.

There is no limit to the number of supported CFexpress cards, SSDs, or other NVMe storage devices you can inspect.

As many as you like.

Card Inspector Pro does not license individual storage devices or impose a limit on the number of cards or drives you can inspect.

Whether you have a handful of CFexpress cards or manage a large collection of photographic storage media, your license covers all compatible devices you choose to examine.

Yes. Each purchase includes two licenses, allowing Card Inspector Pro Version 1 to be activated on two compatible Macs.

Licenses are intended to be transferable, so you can move an activation to another Mac when replacing or upgrading your computer, subject to the activation procedures in effect.

The second license is provided for your convenience. However, because inspection histories are maintained separately on each Mac and do not currently synchronize, we recommend using one Mac as your primary inspection system.

This allows successive inspections of your storage devices to accumulate in a single historical record, providing the most complete basis for longitudinal analysis.

Card Inspector Pro Version 1 is available through a one-time purchase, without recurring subscription fees or a predetermined license expiration date.

Your license permits continued use of Version 1 for as long as the application remains functional on your Mac and its operating system.

Maintenance updates, including potential bug fixes, may be released during the Version 1 product lifecycle. However, the purchase does not guarantee future updates, continued compatibility with subsequent macOS releases, or support for future hardware and operating-system changes.

If a future major version is released, it may be offered as a separate purchase.

Card Inspector Pro is designed for compatible NVMe storage devices, including supported CFexpress cards and SSDs.

Compatibility depends on more than the storage device itself. The reader or enclosure, connection interface, cable, Mac hardware, macOS version, and device firmware can all affect whether the necessary NVMe management information is accessible.

Importantly, a card or SSD may function perfectly well for ordinary file transfers while its reader or enclosure prevents Card Inspector Pro from accessing the controller information required for inspection.

For this reason, compatibility cannot be guaranteed solely from a manufacturer’s brand name, the presence of a USB-C connector, or the ability to read and write files.

We encourage customers to review the published system requirements and compatibility information before purchasing.

We understand that compatibility with NVMe storage devices and their readers can be complicated.

That’s why Card Inspector Pro includes a 14-day compatibility guarantee.

If you purchase Card Inspector Pro and discover that it cannot inspect your intended storage device because of an incompatibility with your device, reader, or supported Mac configuration, you may request a refund within 14 days of purchase.

Please contact support with a description of your equipment and the compatibility issue so we can assist you.

The compatibility guarantee is intended to give customers confidence that they can evaluate the application with their own equipment without assuming all NVMe devices and readers will be supported.

Card Inspector Pro performs its device inspections locally on your Mac.

It does not require cloud-based analysis or the uploading of your storage-device measurements to an external service.

An internet connection may be required for purchasing, downloading, activating, or updating the application, depending on the licensing and distribution arrangements.

Card Inspector Pro stores inspection history locally on the Mac performing each inspection.

These records allow the application to compare successive observations, examine changes in reported device condition, and evaluate operating behavior over time.

Inspection databases do not currently synchronize between Macs.

If you inspect the same CFexpress card or SSD on two different Macs, each installation maintains its own independent history. Neither installation automatically incorporates observations recorded by the other.

For this reason, we recommend designating one Mac as your primary inspection system and using it consistently for routine inspections.

Your second activation remains available for convenience, such as inspecting devices when traveling or using another workstation.

Synchronization between installations may be considered for a future release, but it is not currently supported.

No. Card Inspector Pro does not inspect the contents of your photographs, videos, or other personal files.

Its device inspections retrieve available information reported by compatible NVMe storage controllers.

The application does not write benchmarking files, perform stress tests, erase storage media, or modify the files stored on the devices being inspected.

Yes. Customers receive access to the complete Card Inspector Pro User Guide at no additional charge.

The guide provides detailed explanations of the application’s features, reported measurements, assessment classifications, historical analysis, and other information intended to help users understand and make effective use of the software.

Card Inspector Pro will be available for purchase and digital download through our online storefront.

After completing your purchase, you will receive instructions for downloading and activating the application.

Additional details about license activation and installation will be provided when purchasing becomes available.

For questions about compatibility, purchasing, licensing, or using Card Inspector Pro, please contact:

support@cardinspectorpro.com

When reporting a compatibility problem, it is helpful to include your Mac model, macOS version, storage-device model, and reader or enclosure information.