Lexar recently introduced the "largest lexar microSD memory in A2 class". Of course, the capacity of this memory is 512 gigabytes, but what distinguishes this microSD with this amount of capacity from the rest of the memory is its A2 typing.
The microSD card is designed to transfer apps and games from internal memory to micro devices. In these cases IOPS is more important than reading and writing sequentially on a memory card.
The A2 rating confirms the speed of 4000 IOPS for reading and IOPS 2000 speed for writing on memory cards. These speeds are 1500 and 500 IOPS for the Class A1 rating.
Generally, Class A ratings were created after the microSD was able to store and run apps and games. In fact, there are different classes for measuring microSD memory cards, with Class A being one of them that measures the speed of microSDs.
The A2 rating advantage over A1 is actually the support of the A2 microSDs from the possibility of queuing functions and commands as well as having a cache.
But lexar microSD memory is also a desirable option for video storage. The lexar microSD memory can easily record videos with a resolution of 4K. This suggests that the micro-memory can maintain a continuous write speed of 30 MB / s. It should be noted that the peak speed of writing this memory card is 100 MB / s, which is, of course, not very stable.
Samsung Evo Plus card with 512 gigabytes of internal memory has a UHS-U U3 rating but no A2. Both Micro Integral and PNY microSD memory cards with 512 gigabytes of internal memory have a V10 rating but do not have Class A ratings.