Choosing the right SD card for surveillance cameras

Choosing the best SD card for security cameras is a critical part of ensuring the reliability of a surveillance solution. Now with edge storage on security cameras becoming the primary storage solution, knowing what to look for in an SD card has become vital.

Edge storage in surveillance cameras has made building a surveillance solution more flexible and more affordable; however, the reliability of edge storage has been questioned in the past. A big part of these concerns was due to the insufficient abilities of standard retail SD cards. As a result, it has made choosing the right Secure Digital memory card (SD card) for security cameras a critical component of an effective surveillance solution. Without the right SD or microSD card to store and write video data, the reliability of a surveillance system could be extremely compromised.

Globally, the SD card market is forecast to surpass US$8.9 billion in revenue by 2022, according to a report by Persistence Market Research. Advancements in NAND technology are expected to drive the applications of SD memory cards. These advancements are also helping manufacturers develop SD cards better suited to the needs of video surveillance. We talked to some of the leading SD card manufacturers to ask them what makes a good SD card for security cameras.
 

Security camera needs

Unlike other types of cameras, surveillance cameras have different storage requirements. From the different environments in which security cameras are deployed to the need for 24/7, continuous data writing, security cameras require something more than the standard retail SD card can offer.

“The vast majority of microSD cards available in the market today are intended for consumer use in digital still cameras (DSCs), car dash cams or home cameras; they are not designed for commercial and industrial edge storage in IP video surveillance cameras,” explained Joey Lin, Senior Segment Marketing Manager at Micron Technology. “As a result, edge storage is viewed as ‘unreliable’ by many systems integrators and installers.”

The majority of users do not understand that the lifespan and quality of SD cards used in edge recording can vary significantly depending on the quality of the card selected. Selecting the wrong quality SD card could therefore result in costly field failures that may occur within months of deployment.

“A common mistake today is the use of retail microSD cards in video surveillance deployments,” Lin said. He explained: “The example is that a 64 GB retail card will quickly wear out in a typical video surveillance system with a continuous 8 Mb/s bit rate. If recording to a retail microSD card for 12 or more hours a day, the retail memory card will likely fail within months of deployment.”

Lin pointed to the following as the major differences between memory cards currently available in the market: the NAND flash technology used in the card; how well the firmware is optimized for 24/7 video recording; and how the NAND is tested and screened to improve overall product reliability.

To meet the storage requirements of security cameras, it is advised to select a card with high endurance and environment hazard protection — for example, tolerance to very high or low temperature and humidity. “Security cameras may record 24/7 whatever the weather condition, and they need a card able to record without error with sustained performances and a limited risk of failure. It is key to select the correct SD card,” said Robert Allen, Director of Marketing and Technical Services for EMEA at Kingston Digital. “Another important specification is the recording resolution and frame rate of the surveillance camera. If an SD card data transfer speed does not match the camera’s requirements, it will affect the recording.”

One of the biggest differences between edge storage in a security camera versus other cameras is the heavy workload to the edge storage device. A security camera requires high endurance capability and recording performance to meet the needs of 24/7 high quality video recording. 

“From an endurance perspective, edge recording in an IP camera is one of the heaviest workloads for memory and can quickly wear-out a consumer-grade retail microSD card, after which storage is not possible until the card is replaced,” Lin said. “For an application that needs 24/7 continuous recording, firmware must be tuned to support minimum steady state performance to guarantee all frames are recorded.”