The V30 rating is part of the Video Speed Class system, which was introduced to meet the needs of users recording high-definition and 4K video. The Video Speed Class, denoted by the letter “V” followed by a number, indicates the minimum sustained write speed that the SD card is capable of. In the case of V30, the “30” means the SD card can maintain a continuous write speed of at least 30 MB/s.
This sustained write speed is particularly important for video recording because it ensures that the SD card can handle the continuous flow of data required to store high-quality video without any interruptions. For instance, 4K videos and high-bitrate recordings require a high write speed to ensure that the video file is stored smoothly without dropped frames or corrupted footage.
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