Comparison Transcend Premium 400x microSD UHS-I 16 GB vs A-Data Premier microSD UHS-I U1 32 GB

The nominal capacity of a memory card is the amount of data that can be written to it. For technical reasons, the real working volume of modern memory cards is usually somewhat less than the nominal one (for example, 14.9 GB with the claimed 16 GB). However, with the same type of card, differences in nominal capacity usually correspond to differences in actual capacity: for example, a 64 GB SDXC card will actually have twice the capacity of a 32 GB card of the same card.

Recall that different types of media have different limits on the maximum volume; see "Type" for details. And a specific volume is most often chosen by the manufacturer not arbitrarily, but from a list of standard options. The most widely used cards nowadays are 16 GB, 32 GB, 64 GB, 128 GB and 256 GB ; capacities of 8 GB or less are considered modest, with the most capacious models holding 512 GB or more.

Note that the price of the card directly depends on this parameter. Thus, many models are available in several variations, differing solely in capacity; and it is worth choosing by volume depending on the types of data that are planned to be stored on the card. Of the popular formats, text documents occupy the least space — usually tens, at most hundreds of kilo...bytes. The size of a photo from a modern camera or an MP3 file is already calculated in megabytes, music in lossless formats "weighs" already tens of megabytes, and the volume of a video depends on its duration, resolution and the codecs used.

Factor describing the maximum speed of the card in read mode. In this case, 150 KB / s is taken as a unit; thus, for example, a speed value of 533x corresponds to 150 * 533=79,950 KB / s, that is, about 80 MB / s.

In general, this parameter is quite specific; in fact, it is easier to focus on the directly claimed reading speed (see below). However, sometimes it is not indicated — in such cases, the speed value will be primarily useful.

The maximum speed of reading data from a memory card.

Any modern memory card provides sufficient reading speed for simple everyday tasks — like copying photos from a camera to a laptop. Therefore, it makes sense to pay attention to this parameter mainly in cases where the card is purchased for professional use, or if high speed is critical for you — for example, if you often have to copy photos from the camera in a hurry. In doing so, two points should be taken into account. Firstly, the corresponding speed must be supported by the card reader where the card is used. Secondly, this paragraph indicates the theoretical maximum — in perfect conditions; the actual reading speed may be lower (if we are talking about cards with UHS, this speed can be estimated by the UHS class, see above about it). Nevertheless, it is quite possible to compare different models of cards by this indicator: differences in theoretical speed usually quite correspond to the difference in actual speed.

Manufacturer's warranty provided for this model.

In fact, this is the minimum service life promised by the manufacturer, subject to the rules of operation. Most often, the actual service life of the device is much longer than the guaranteed one. But an indicator of 5 years suggests that the memory card is more likely to be lost or become irrelevant. You can also come across a lifetime warranty, but in this case it is better to clarify the details of what it applies to. And in any case, it implies a certain period of time, though measured in decades. In addition to confirmation of reliability, such a guarantee allows you to contact the supplier after a while to eliminate possible problems (of course, not mechanical). But the difficulties in implementing this procedure (the representative office is located only in large cities) and the rare cases of the need for this (after all, it is easier to buy a new flash drive, with the exception of vital information on the old media) make the lifetime warranty more of a marketing ploy than a cool chip.