Guide: explaining the notation on memory cards

Today, a memory card is an indispensable element. We use them in almost any portable equipment, from smartphones to video recorders and modern cameras.

The most popular memory card formats

Currently, we can talk about two memory card formats that are actually used. These are SD or Secure Digital and CompactFlash. The first ones are used almost everywhere. This is by far the most popular standard. We use them in smartphones, cameras, video recorders and other equipment. Wherever a memory card is required, you can expect an SD or microSD slot. On the other hand, we have CompactFlash memory cards, which are only used in semi-professional and professional SLR cameras. They are noticeably larger and more expensive. Gradually, they are also being replaced by SD cards.

Let's start with SD cards, that is, Secure Digital. This standard was created in 2000. Due to the use of the FAT file system, they could initially have a maximum capacity of 2 GB. Over time, version 2.0 was introduced by the FAT32 file system, which increased the capacity to 32 GB. These cards were named SDHC (Secure Digital High Capacity). Today, in the era of 4K Ultra HD resolution, even 32 GB is not enough.

Classes of SD memory cards

Multiple cards are used on SD memory cards to specify the minimum speed. Initially, four classes were used: class 2, Class 4, Class 6 and Class 10. Each means sequentially 2, 4, 6 and 10 MB of minimum transfer rate. It is important to note that this is the minimum, not the maximum speed. Over time, this was no longer enough, so the UHS bus and the designations U1 and U3 were introduced. The first one means a speed of at least 10 MB/s, and U3 is already 30 MB/s. In practice, the U1 models turn out to be faster.

During the presentation of the SD 5.0 standard, more markings appeared: V6, V10, V30, V60 and V90. The letter "V" stands for video, after which it is easy to conclude that these formats were created for filmmakers. The following figures tell us about the minimum write speed in MB/s, that is, V90 to 90 MB/s. Again, it may seem that V10 is exactly the same as Class 10 or U1, but in practice the class defines the minimum speed for a completely different situation. Therefore, these signs cannot be treated equally.

The new designation is A1

The A1 designation is new. So far, there are not many memory cards on the market that could boast such a symbol on the box and case. Meanwhile, for demanding users, this is a very important sign. It has nothing to do with the speed of reading or writing. The A1 designation informs us about the number of supported input and output operations. This is very important, for example, in smartphones, if we decide to transfer part of the application to a memory card.

Models without this label, even very expensive ones, usually support no more than a few dozen I/O operations per second. A1 memory cards must support at least 500, which is many times more than standard models. That is why A1 marked cards are recommended for the most demanding users who are looking for a universal memory card, especially for smartphones.

Professional models, that is, created for professionals, are quite popular. However, in practice, their use in many cases does not make sense. Often, Pro cards are noticeably worse in a number of parameters. This can be seen even after the test on microSD cards, where the most expensive Samsung model turned out to be... the worst in terms of the speed of accidentally saving small files. Найдите свою идеальную шлюху или проститутки Керчь - они просто великолепны. Особенно в постели с клиентом, настоящие индивидуалки.