A Complete Guide to Micro SD Cards

Micro SD cards are small removable memory cards in which data can be stored. They are a specific type of SD (Secure Digital) card. There are many different models of SD cards available in a range of sizes, both in terms of physical dimensions and storage capacity. However, all SD cards are designed for use with typically portable digital electronic equipment which creates or produces data and features special slots designed to hold SD cards.

As they are portable memory cards, SD cards are typically placed inside hardware devices where additional or external memory is needed to manage and store data.

This includes:

• Digital cameras, video cameras, and action cameras e.g. GoPro
• Mobile phones and tablets
• Computers such as Raspberry Pi
• Small GPS devices and satellite navigation systems
• Portable PCs
• Portable media players

Micro SD cards can be used to store a wide range of different data types. This includes photos, videos, music files, documents, app data, and even device processing data.

Another way to classify micro SD cards is by the speed at which they process data.

Transfer speed is a parameter that indicates the minimum speed at which data is written on the memory card. Generally, the faster the speed, the more modern and higher performing the card.

These speed classes are designed to standardise memory card speed ratings by referring to the minimum sustained write speed for a micro SD card.

Speed class types include:

Micro SD card size typically refers to the card’s storage capacity or the amount of data it can hold.

Values can vary significantly but common options include:

• Micro SD card 32GB
• Micro SD card 64GB
• Micro SD card 128GB
• Micro SD card 256GB
• Micro SD card 512GB

When data is stored, it takes up a certain amount of space within the card, depending on the file size. For instance, a video file will be larger than a single image file. Therefore, the file sizes and the amount of data stored will determine when the micro SD card will ‘fill up’ or run out of available memory to store additional data.

Although they broadly perform the same function, it is important to select the best micro SD card for your device or usage requirements. There are several key features on which performance depends:

• Device compatibility
• Security features
• Speed class
• Storage capacity

When choosing a micro SD card, it is therefore important to ensure it has suitable speed, storage capacity, and security features to meet your needs.

The differences between micro SD and micro SDHC cards are as follows:

• Capacity: Micro SD cards have a maximum capacity of 2GB, whereas micro SDHC cards have a maximum capacity of 32GB
• Compatibility: Micro SD cards work in any micro SD slot, whereas micro SDHC works only with devices that support either SDHC or SDXC