Speed Class
Most important on this one is that there are three ratings classes and they are NOT COMPATIBLE.
These are x, Speed Class and UHS-I Speed Class.
Unless your device calls out the UHS-1 interface it will not recognize the card.
Unrated , Speed Class and x rated cards are all compatible.
I have subpages for each of three ratings that explain them more fully.
What is it ?
The ratings systems all cover the speed the card can read data. "speed class' and UHS-I also cover write speed. This comes into play on video or large still pictures. If you see an hourglass while your camera is storing a photo you may want a faster card,
