UHS Bus Interface
UHS-I provides faster bus speed using just one row of pins, while UHS-II uses two lanes for even faster data transfer via two rows of pins. The symbol "I" means UHS-I, and "II" means UHS-II. Please make sure your device supports the same standard to benefit from the increased speeds.
Speed Class
Speed Class defined by the SD Association includes Class 2, 4, 6 and 10. Each class is defined for a minimum sequential write speed. For example, Class 10 will ensure a minimum data transfer rates of 10MB/s.
UHS Speed Class
UHS Speed Class includes UHS Speed Class 1 (U1) and UHS Speed Class 3 (U3). UHS Speed Class 1 supports a minimum 10MB/s write speed, whereas UHS Speed Class 3 supports at least 30MB/s write speed.
Video Speed Class
Video Speed Class is defined to answer a demand for high resolution and high quality 4K8K video recording. V60 (60 MB/s) and V90 (90 MB/s) can support 8K resolution, while V6, V10 and V30 capture high-definition and 4K resolution and ensure minimum sequential write speeds of 6 MB/s, 10 MB/s and 30 MB/s respectively.