The Speed Class indicates the minimum continuous data transfer rate when writing video files to a memory card. The Speed Class number shows the transfer rate in megabytes per second. Class 2 cards are designed for a minimum continuous transfer rate of 2 MB/s, while Class 10 cards are designed for a minimum continuous transfer rate of 10 MB/s. The speed classes are divided into classes 2, 4, 6, and 10. For Full HD video (1080p), a minimum of Class 6 is recommended.

The Video Speed Class includes five speed levels: V6, V10, V30, V60, and V90, with the number indicating the minimum write speed in megabytes per second (MB/s). By combining a device with a Video Speed Class designation and an SD memory card with the same Video Speed Class designation, you can capture memories in the best quality. The fastest options, V60 and V90, support 8K resolution, while V6, V10, and V30 reliably capture Full HD and 4K resolution.

SD cards with the UHS-II standard offer up to 312 MB/s in compatible devices. As with UHS-I, there are also UHS speed classes here: U1 for Full HD videos and U3 for 4K videos. Memory cards that support UHS-II are backward compatible and can be used in devices without UHS support (with limited performance).