Not every SD card is created equal. In fact, advances in edge storage mean that SD cards optimized for surveillance are a world away from traditional SD cards with more limited functionality and endurance.

Yet misperceptions around SD cards are pervasive in the market. Where the belief persists that ‘any SD card will do the job’, it can lead to missed opportunities for organizations. For example, it can result in organizations choosing sub-optimal SD cards for their devices – perhaps opting for edge storage options with lower endurance that wear out more quickly. Additionally, where organizations are unaware of the use cases where quality edge storage can play a key role today, they are often losing out on the performance – and financial – benefits that high endurance SD cards can offer.

SD cards – but not as you know them

The legacy perspective is that SD cards are all much alike, but this is not the case. The advances that have led to ever more powerful and “complete” surveillance solutions at the edge of the network have demanded a new generation of edge storage solutions. From higher endurance to built-in encryption to health monitoring features, a new breed of SD cards optimized for surveillance exists.

As the traditional camera-server model has evolved over time, edge storage is increasingly playing a key role within organizations’ surveillance systems. With the right SD card, organizations can unlock more functionality and therefore more benefits from their surveillance solution.

Yet the false belief that any SD card is interchangeable for another risks organizations failing to get the best out of their surveillance system. After all, the greater complexity of devices today inherently requires a more advanced level of storage at the edge. Here we’ll challenge widespread misperceptions around edge storage and set the record straight on the capabilities of this technology today.

Myth #1: Edge storage is only useful for redundancy

This is no longer the case. While it’s true that edge storage can be used to increase system reliability as a back-up through continuous recording in case of network or server failures, these solutions have evolved to the point that they can also be used as a valid primary storage mechanism.

The fact is that SD cards have uses far beyond backing up video data. Many organizations are successfully using edge storage solutions as a primary storage option for capturing a much richer set of data, including metadata. As an example, if connecting a radar device to a visual camera as part of a more “complete” edge solution outside a school, the radar requires an SD card to collect statistics, from monitoring how many vehicles are passing and how fast they are going to the directions they are heading in. In this instance, the SD card offers vital primary storage.

Just as edge solutions have evolved into “complete” – and more complex – offerings at the edge that can capture so much more data, edge storage solutions have inherently advanced in line with that to support the operations and functioning of those solutions.

Myth #2: SD cards don’t last as long as a network video recorder (NVR) / recorder system

While it’s true that lower grade SD cards have more limited lifetimes than NVRs, the alternatives on the market which have been optimized for surveillance are built to endure.

On average, cameras within surveillance systems need to be replaced every 8-10 years. Yet some higher endurance SD cards can last for more than ten years. Close collaboration between manufacturers and suppliers has enabled the design and specification of these high performing SD cards, enabling superior wear resistance and making them as high endurance as possible. In fact, if you choose the right sized card and know what retention time you require, the card will most likely outlive the camera.

Myth #3: Edge storage doesn’t have the capacity for high-quality video surveillance

Contrary to some beliefs, high-resolution video can be recorded locally (and effectively) on high performing SD cards, either as primary storage or as redundancy for failover recording in case of lost connections. Additionally, in applications with bandwidth limitations, live video can be viewed in low resolution, while high resolution video is recorded locally on the card.

The retention time of the card depends on how the cameras are configured to record at different frame rates and resolutions, depending on motion detection, alarm events and hours of the day. For example, the retention time of a high endurance SD card with 128 GB storage can vary from 20-215 days, depending on the camera configurations and resolution required. Even smaller 64 GB SD cards’ retention times can range from 10 to more than 100 days.

Myth #4: Edge storage use is limited to serverless environments

The fact that edge storage is so useful for self-contained surveillance solutions in locations without network connectivity, such as onboard installations on trains and buses, can drive the belief that SD cards are limited to those use cases. However, this is far from true.

SD cards do provide an affordable edge recording solution wherever network bandwidth is limited or absent, but they can do so much more. When integrated with VMS (video management software), edge storage helps create more robust and flexible video surveillance systems for mission-critical installations, such as airports or mass transit hubs. In such installations, edge storage in cameras that cover entrances and exits could be a critical part of a strategic backup plan.

Importantly, edge storage can also be used to capture video and metadata (such as statistics from a radar device) at the edge. This can then be analyzed on a server to spot trends, such as traffic trends through surveillance at a road outside a school.

Myth #5: SD cards are a hygiene factor; not a strategic purchase

Many cameras come with an SD card, perpetuating the idea that they are a hygiene factor rather than a strategic purchase. This might have been the case in previous decades, but edge storage now provides a range of advantages that can drive business value.

For instance, many organizations are investing in powerful edge solutions so it’s vital that the accompanying edge storage meets the requirements to derive the maximum benefits from that investment. Using substandard SD cards within complex edge solution offerings can become a false economy – saving initial costs but preventing optimal performance in the long run.

Similarly, consider the potential energy and financial savings made possible by reducing the number of servers you need to buy, run, and maintain to support your surveillance system. By shifting to a hybrid cloud system that uses a mixture of server and edge storage options, you can both tailor the system to your exact requirements and reduce the costs associated with servers by incorporating more edge storage solutions. While high endurance SD cards may entail a higher initial cost than their lower endurance counterparts, these surveillance cards can be deployed strategically within a hybrid system to minimize the TCO of your system, ultimately benefitting the bottom line.

Key considerations

While high endurance edge storage solutions offer a wide array of benefits to every sector, there are some key factors to consider.

In some cases, high frame rate video will need to be retained for long periods of time, in case of incident investigation or legal requirements. This will eventually cause limitations with regard to edge storage. As a result, good discipline will be required around the regular transfer or offload of data to server-based storage.

Additionally, while it’s rare, it’s possible for cameras to be attacked or physically compromised, whether by criminals who feel their identity might have been captured or as an act of vandalism. With edge storage, if the camera is lost, the data is too – though choosing surveillance devices and SD cards that offer encryption means you don’t have to worry about an unauthorized person accessing the data, even if the SD card is stolen. To avoid losing all data through theft, discipline around video data transfer or offload is again required.

Making the right choice for your needs

It’s time to rethink what you know about edge storage. Not every SD card is created equal: you will need to choose the right option for your needs in terms of storage size and retention time if you are to reap the maximum benefits.

Consider where you could deploy edge storage solutions to create efficiencies and drive cost savings, and where it makes more sense to rely on options such as recorders and servers. The right combination can offer increased business value by reducing the cost and maintenance burden of NVRs and servers, but that combination will be unique to each customer and use case.

Find out more about AXIS Surveillance Cards and how they are optimized to support your surveillance needs.

AXIS Surveillance Cards