Speed Class Standards for Video Recording

There are four different speed classes -- 10, 6, 4, and 2. Class 10 is the fastest, suitable for “Full HD video recording” and “HD still consecutive recording.” Class 2 is the slowest, suitable for standard definition video recording, it is able to see the MPEG4 and MPEG2 movies, watch SDTV and digital video camera shooting. Classes 4 and 6 are both deemed suitable for high-definition video recording. For class 4 it can play HDTV smoothly, digital camera burst shooting. For class 6, it is able for SLR camera to burst shooting and it can meet with professional equipment requirements.

An SD card’s speed class is identified on the SD card itself—just look for the logo. You’ll also see the speed class on the online store listing or on the card’s packaging when purchasing it. For example, in the below photo, the middle SD card is speed class 4, while the other two cards are speed class 6.


If you see no speed class symbol, you have a class 0 SD card. These cards were designed and produced before the speed class rating system was introduced. They may be slower than even a class 2 card.


 The minimum sequential write speed of speed class 10 is 10mb/sec.

The minimum sequential write speed of speed class 6 is 6mb/sec.

The minimum sequential write speed of speed class 4 is 4mb/sec.

The minimum sequential write speed of speed class 2 is 2mb/sec.


 The bit rate of 4k is 6mb/sec to 7mb/sec and it’s less than 10mb/sec, so that means it is much more enough to use the Class 10 SD card for our action cameras.


PS: What is the data rate?

Video data rates are given in bits per second.The data rate for a video is the bit rate. So a data rate specification for video content that runs at 1 megabyte per second would be given as a bit rate of 8 megabits per second(8 MBPS).


Please note:  If your video plays very slowly on your computer, it should be the problem of your compuer. It may be the configuration of hardware is not good enough, or else it may be your player's problem. If the video plays on the camera slowly as well that should be the problem of the sd card.

Thank you and if you have any feedbacks or questions please feel free to contact us at pr@soocoo.cc