SD memory cards as a technology have a proven track record as the most successful removable storage form factor of all time. They are a simple, trusted and low-cost solution. They are also supported by a very large percentage of the consumer electronics industry, and SD slots can be found on many everyday devices, including smartphones, tablets, DVRs and in-car video recorders.

After 16 years, the removable storage market is still growing, and many market research companies agree that SD memory cards will continue to be adopted outside the traditional and mature imaging market as the preferred form factor for removable storage. In recent years, there has been a mini explosion in the variety of uses for SD memory cards – most notably for IoT, mobile, automotive, drones and industrial applications (plus many more), all of which have significant growth prospects in the coming years. These are exciting times for the industry, proving that the simplicity of using a robust technology, such as the SD memory card, as a removable and expandable storage solution has value to both OEMs and consumers.

But with new opportunities come challenges: OEMs and industrial customers new to using SD memory cards need to understand that not all cards are created alike.

What SD Standardization Means to OEM UsersD

Standardization is sometimes not fully appreciated by the average consumer, but the benefits are everywhere. The consumer is guaranteed interoperability because of collaboration between the device and SD memory card manufacturers, which both design to the same specification. Therefore, simply knowing that the card you bought at a local shop will work in any device is extremely reassuring. Plug and play is not just convenient; it is a must-have requirement – but this wasn’t always the case.

Some of us remember the early days of removable memory cards, when there were so many competing form factors that cards were labelled by a veritable alphabet soup of letters that had little meaning to the average user. The success of SD cards in the early 2000s proved that interoperability was the way to go, and as the form factor became more established, lesser form factors struggled for design-wins and just couldn’t compete anymore.

The utility of consumer SD memory cards is often mistakenly extended to the OEM and industrial space. People have positive experiences using the cards in their home devices and therefore recommend the same type and brand of cards for work projects, assuming the card will work and behave the same way. However, this creates an inadvertent issue because industrial applications require features not found on conventional consumer cards. Not everybody understands the differences in types of cards; the added features that certain industries and sectors require; and the type of support services available. When used in applications and devices that benchmark minimum levels of performance or endurance, a focus on function is critical, and having the right card for industrial applications is essential.

Despite having worked with OEMs all over the world, rarely have we seen engineers at the center of the entire decision-making process from concept to delivery. An OEM can make better decisions by taking some simple steps, asking the right questions and involving engineers at the start of a project. The result can save money in the long term and ultimately improve their customers’ experience.

OEMs: Understand Form, Fit and Especially Function

As SD technology evolves to meet the modern needs of the mobile and industrial computing market, it is important that OEMs take the time to understand the differences between cards and their practical uses within different product sets.

There are three words that product engineers and manufacturers use a lot: form, fit and function. When referring to a SD memory card, what do these mean?

  • Form refers to the physical attributes of the card – the size and weight of the product
  • Fit refers to the interface – how it connects to a device to ensure it doesn’t fall out or come loose
  • Function relates to product differentiation

Both the form and fit of an SD memory card are part of the mechanical and electrical specification, so it should always be the same size and connect in the same way, regardless of the device in which the card is being used. These cards are also backward compatible, a massive advantage for anyone developing products with a longer lifespan.

The function, however, is where card manufacturers differentiate their products by determining what type of flash memory is used and what features they want to have in the controller. A lot of effort goes into component selection, screening and testing to select materials and components for different types of cards. Function also can be the purpose of the card, because it defines how it should perform, and this is where product and design engineers need to take notice.

Industrial Users Need to Think Differently

Industrial customers need to think differently than consumers and should focus less about the retail branding and more on what’s inside the card and available support services and information. The brand is still important, but the label on the outside doesn’t always tell you what is going on inside or what features the card manufacturer has put into its product.

An industrial user instead should think about the function of the card, the environment where the card will be used and if there is a speed requirement – e.g., do you need to upload or download files within a set amount of time, or is endurance and reliability a key requirement? If so, then you need to specify a card that offers these features and meets your requirements.

Before any purchasing decision is made, industrial customers should consider the application, consult their engineers, agree on a list of must-have features and set an expectation for how they want the SD memory card to perform. The supplier should then be able to review this and provide a gap analysis of the differences and engage with the card manufacturer to ensure they fully understand what the application is, so they can recommend the right solution to meet the customer’s needs. Some manufacturers can run life usage models, simulate the workload and even advise an OEM how to optimize the performance of the card.

Tips & Advice

Asking the right questions and checking what’s available in the market before making a commitment is essential. Consider the following:

  • Take time to understand the technical as well as the commercial requirements; both are equally important.
  • Procurement managers are always looking for the lowest cost, but they must trust their engineers to define the card’s technical requirements before making a purchase.
  • Think about the end-user experience, because an incorrectly specified card may not perform well – but it isn’t the card’s fault; it’s due to a failure to specify the correct card.
  • Define the key performance requirements. You don’t have to use the same technical language – think of yourself as an end user and what type of experience would you like them to have. Write a basic specification and determine the most important features they need such as:
    • Endurance
    • Reliability
    • Read or write speed
    • Environmental tolerances
    • SMART reporting
    • Life-monitoring tools
    • Power management


Choosing an SD card that is right for an application can appear to be a daunting and challenging process, but with the right advice and a little research, you can make better informed decisions.

There is a big responsibility on OEMs to understand that while all SD memory cards should work the same way, you get what you pay for and each type of card will perform differently. The cheapest isn’t always best; sometimes a better quality or type of card will actually save a company money by performing better and longer and delivering an excellent user experience.

Likewise, card manufacturers must ensure they are producing SD products that provide the right option variables for the right markets and that are consistent in quality of design. This will ensure that the end products function safely, efficiently, and to their best ability for the end users. There is never a one-size-fits-all solution that will meet all budgets.



Paul Norbury is a SD Association Board member and the chief executive of multi-award-winning company Cardwave, which has offices in Devizes, Wiltshire and Dallas, Texas. Norbury can be reached at

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