The U1 and U3 are UHS Class speeds that show the minimum write speed. U1 cards support at least 10Mbps write speed and the U3 cards will deliver at least 30MBps write speed. Note that these are minimum write speed values. It is possible for a U1 card to give a write speed greater than 10MBps, say 15MBps, as well. The Speed Class, that’s denoted numeric value within the letter ‘C’ on your microSD card also denotes the sequential write speed.

use of the content you supply does not violate these Terms of Use and will not cause injury to any person or entity. Hardware that supports microSDXC slots will not automatically support every size of card in this format. If you plan on using your microSD card with your PC say for moving files on and off, you need to make sure that your PC supports the file system that the card is formatted with. When looking for a MicroSD, it is essential to buy one that is just right for its intended purpose. This means that buying a card that’s not just large enough but also fast enough and not automatically the fastest or largest one out there. There are high capacity cards like UHS-II U3 that comes with a steep price but you will not always notice the benefits it offers. UHS Speed Class on the other hand indicates the minimum write speed for microSD cards that support the UHS-I and UHS-II bus speeds. Its classes are the following; that is, or may reasonably be considered to be, defamatory, libelous, hateful, racially or religiously biased or offensive, unlawfully threatening or unlawfully harassing to any person or entity;

Video Speed Class

MicroSD comes in 3 formats; SD, SDHC and SDXC, which will determine whether or not the card you’re about to buy will be compatible with your gadget. Both full-sized and micro cards are based on the same spec and each format is defined in the SD spec, howeer the don not work in the same manner. For example, if the card slot on your gadget only supports MicroSDHC card, then a microSDXC card will not work on it.

The Speed Class indicates the minimum write speed of a memory card in MBps or megabytes per second. The four Speed Class are as follows:

There are two forms of memory cards, SD and microSD. SD cards are basically used in bigger devices such as video cams and digital cameras. They are also a bit larger than your average postage stamp. MicroSD on the other hand are used more in gadgets like tablets and smartphones. They are smaller than full sized SD cards. There’s also a third form, the MiniSD, but this was used widely as a transitional form factor in the mid-2000s before the popularity of MicroSD. Today MiniSD cards are rarely seen. If you’re in need for a new one for your mobile phone, tablet, camera or for some other reasons and, there are several factors you need to consider first before buying and we have all the key information covered here. Always remember that it sometimes pays to choose wisely. What makes the U1 and U3 memory cards more advanced than those in the Speed Class are that they use one of two UHS bus interfaces: There are two types of speed indicated on an SD card “C’ and “U”. Each SD or Micro SD card has a speed rating, called a class. Larger class numbers correspond to a faster level of minimum performance, allowing files to be copied or recorded at a higher speed. The class rating system is actually quite simple to remember: the number after each Class corresponds to the minimum sequential read speeds, in MB/s. So Class 2 is 2MB/s, Class 6 is 6MB/s and so on.