Speed Class Rating
The SD Association defines standard speed classes indicating minimum performance to record video. These are defined in terms of suitability for different applications:
- Class 2 for SD video recording (2 MB/sec)
- Class 4 and 6 for HD ~ Full HD video recording (class 4: 4 MB/sec, class 6: 6 MB/sec)
- Class 10 for Full HD video recording and HD still consecutive recording (10 MB/sec)
- UHS Speed Class 1 for real-time broadcasts and large-size HD videos
The specification defines these classes in terms of performance curves which translate into the following minimum performance levels (on an empty card)