But did you know that all memory cards are not the same and they belong to different classes of cards. Yes, each class is different from the other one and not all classes are supported on your devices. Read on to find out more about what are the different kinds of microSD cards and which one fits the bill for you. The card will probably have for instance both the U1 and V3 markings. If your camera knows the 'V technology', you get 30 MBps. If not, you only get the standard U1 10 MBps. Learn the advantages of using APIs, microservices, and DevOps together. SD cards are available six different speed classes, from slowest to fastest: Class. With all the marking that you find on and SD card like SDHC, SDXC, Class Rating.