Speed class
A characteristic that describes the minimum write speed to the card. It is given for SD and microSD cards (including their variations, see "Type") and is indicated by a number indicating the speed in MB / s: for example, class 10 corresponds to 10 MB / s.
Higher speeds provide more options, but come at a higher cost; in addition, it must be supported by the equipment where the card is used. So the choice for this parameter depends on the capabilities of such equipment and specific tasks. High speed is of key importance for video recording: for example, for video in Full HD (1920x1080) you need a card with a class of at least 4, and preferably 6 or even 10 (such characteristics already allow you to work with an increased frame rate).
Note that in the characteristics of many memory cards, you can see seemingly inconsistent figures. For example, a class 10 model can correspond to UHS Class 3 (which means the speed is no longer from 10, but from 30 MB / s) and the video recording class V60 (and this is already from 60 MB / s); and the overall write speed for it can be claimed at an even higher level — for example, 80 MB / s. All of these options are described in detail below; and here we note that there are no inconsistencies here. The fact is that the data regarding the UHS capabilities and the video recording class are relevant for operation via the UHS bus; if the card reader does not have such a bus, then the card's capabilities are limited by the...general speed class. So, the model from our example in a card reader without UHS will be able to issue a maximum of 10 MB / s; and if you have UHS, it will work at least 60 MB / s, which does not contradict the requirements of UHS Class 3 (at least 30 MB / s). The overall write speed is usually indicated by the theoretical maximum, and in fact its value is often noticeably lower.
Read speed
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.
Adapter included
An additional
adapter is included with the memory card.
The adapter is a device with which the card can be installed in a non-native format card reader. Nowadays, microSD cards are mainly equipped with such a device — adapters are designed to install such media in a slot for a full-size SD card. This is convenient primarily for exchanging data between portable gadgets like a smartphone / tablet and larger equipment like PCs and laptops — for example, to copy pictures from a smartphone camera to a computer or music from a computer to a smartphone.
Manufacturer's warranty
Manufacturer's warranty provided for this model.
In fact, this is the minimum service life promised by the manufacturer, provided that the operating rules are followed. Most often, the actual service life of the device turns out to be significantly 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 find
a lifetime warranty, but in this case it is better to clarify the details of what it covers. And in any case, it implies a certain period of time, although 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 (not mechanical, of course). But the difficulties in carrying out this procedure (representative offices are located only in large cities) and the rare cases of 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 feature.
