How to Choose the Right SD Card for Your Camera

Surveillance cameras are becoming increasingly common, whether for home or commercial use, and they come in various styles. There are stationary, rotating, wall-mounted, indoor, and outdoor options. Regardless of the type, each can meet your needs, protect the people and things you care about, or help capture unnoticed incidents. To ensure reliable recording, it's essential to not only have a high-quality lens but also to choose the right recording products.

For home cameras, memory cards are often inserted independently. However, did you know that besides storage capacity, memory cards also differ in read/write speeds and durability? Different cameras should be paired with compatible memory cards to ensure high-quality recordings.

Storage Capacity

When purchasing a camera, manufacturers may recommend specific memory card capacities based on how the camera records content. Some cameras that record continuously 24/7 require higher-capacity memory cards, while high-resolution cameras (like 3K and 4K) also need more storage for high-quality video. Conversely, those that only record for 30 seconds after motion detection do not have such high demands.

The actual choice of memory card can range from 16GB to 512GB. Currently, there are three types of Micro SD memory cards: SD, SDHC, and SDXC, with differences in capacity. Ordered by size: SD < SDHC < SDXC. SD cards have capacities of less than 2GB; SDHC cards range from 4GB to 32GB; and those greater than 64GB are classified as SDXC. There is also SDUC, but it is not yet widespread, supporting over 2TB.

Read/Write Speed

Even though the speed of the memory card depends on the camera's read/write speed, if the memory card's data recording speed is too slow, it may cause video frame drops or delays, affecting the camera's performance. For example, when recording in Full HD or 4K UHD, you should choose a memory card with a minimum write speed of 70MB/s and support for UHS-I video speed class (V30).

For example, consider the HIKSEMI NEO Home products:

The SD Association categorizes memory cards by speed class. The mainstream Micro SD speed specifications include:

1. Speed Class: Denoted as Class "C," typically includes classes 2, 4, 6, and 10. The card visibly displays the corresponding number, such as "10" for CLASS10, indicating a minimum write speed of 10MB/s. Higher numbers correspond to faster read speeds.
2. UHS (Ultra High Speed): Denoted as "U," typically labeled as U1, U3, etc. Higher values indicate faster read/write speeds per second.
3. V Class (Video Speed Class): This class affects video recording stability. V30 indicates a minimum sustained write speed of 30MB/s, suitable for 4K recording or general photography. While V30 guarantees a minimum continuous write speed of 30MB/s, actual maximum write speeds may be higher, depending on the card’s internal controller and storage architecture. Some high-end models may provide faster burst write speeds, especially during continuous shooting of static images.

Durability

Outdoor cameras must withstand various weather conditions. Similarly, memory cards used in outdoor surveillance cameras need to endure extreme temperatures, humidity, and strong winds. You can choose memory cards with waterproof specifications. Some are specifically designed for harsh weather environments, offering high-temperature resistance, cold tolerance, waterproofing, shock resistance, and X-ray protection.