UHS class
UHS bus version supported by the memory card.
UHS is a data exchange technology used in SD/microSD cards of the (micro)SD HC and (micro)SD XC standards. It allows you to significantly increase the speed of data exchange compared to previous standards; at the same time, media supporting this technology are quite compatible with equipment that does not have UHS - except that the speeds in such cases will be limited by the capabilities of the card reader, and not the card itself.
As for the versions, their names consist of two parts: UHS generation (I or II) and class (1 or 3) - for example,
UHS-I Class 1. Actually, this is the most modest version of UHS found in modern memory cards; in addition to it,
UHS-I Class 3 and
UHS-II Class 3 are popular. The maximum data transfer speed (usually referring to read mode) depends on the UHS generation - it is 104 MB/s for version I and 312 MB/s for version 2. “Class”, in turn, determines the lowest (guaranteed) write speed : it is at least 10 MB/s for Class 1 and at least 30 MB/s for Class 3. Different versions of UHS are quite compatible with each other, except that the speed in such cases will be limited by the slower standard.
Note that for UHS cards, more advanced characteristics may be indicated in other paragraphs - for example, the video recording class (see below) V90 for a UHS-II Class 3 card. There
...is no contradiction here: the speed of 90 MB/s provided by such a card in recording mode, it fully satisfies the “not lower than 30 MB/s” condition provided for UHS Class 3.Video recording class
The video recording class supported by the memory card.
This parameter is indicated for SD/microSD cards and their variations, as well as CompactFlash (see “Type”). In the first case, the format designation V* is used, in the second - VPG*, but the idea is the same in both cases: the numbers indicated instead of an asterisk are the lowest write speed (in MB/s) that the card is guaranteed to provide. This speed is of key importance primarily in video recording, which is why this parameter is called “Video Recording Class”; the higher it is, the higher the resolution and frame rate at which you can record using this card.
The minimum video recording class found in modern SD/microSD family cards is
V6, which already allows you to work with HD and Full HD video. However, for Full HD it is advisable to have a card of at least
V10 level. And the
V30 class already allows you to comfortably work with Ultra HD 4K. Faster cards are also being released - V60 and even V90, suitable for resolutions of 8K and higher.
In turn, in CompactFlash cards you can find models of the
VPG20,
VPG65 and
VPG130 classes
Note that the video recording class may well be higher than the general speed class and/or UHS class (see above). However, there are no contradic
...tions here. UHS class requirements require write speeds of “not less than...”; Thus, for example, all cards with a video recording class of V30 and higher will comply with the UHS Class 3 standard (“not lower than 30 MB/s”). And the general speed class describes the capabilities of the card when working with equipment without UHS support (and such equipment is practically not used in video recording).Speed value
The coefficient describing the maximum speed of the card in read mode. In this case, 150 KB/s is taken as a unit; thus, for example, the speed value of 533x corresponds to 150*533=79,950 KB/s, i.e. about 80 MB/s.
In general, this parameter is quite specific; in practice, it is easier to focus on the directly declared reading speed (see below). However, sometimes it is not specified - in such cases, the speed value will be most useful.
Write speed
The maximum speed for writing data to a memory card.
High write speed is important for tasks that involve storing large amounts of data in a limited amount of time. However, note that this paragraph indicates the theoretical maximum speed for perfect conditions; in fact, this value can be noticeably lower. Therefore, the characteristics of memory cards also indicate the minimum guaranteed write speeds in different modes — the general speed class, the UHS class, the video recording class and/or the class for applications. All of them are described in more detail above. However, you can also evaluate the capabilities of the carrier by the overall speed: other things being equal, a card with a higher theoretical speed will work faster in fact.
As for specific values, speeds
from 4 MB / s and
from 6 MB / s are practically not found nowadays,
from 10 MB / s and from
16 MB / s can be called average indicators,
from 50 MB / s — above average, and the fastest models have a maximum write speed of
100 Mbps or more.
Write protection
The ability to switch the card to read-only mode, which allows you to protect important data from accidental overwriting or erasure. Usually implemented in the form of a mechanical slider switch, the position of which determines the card's operating mode. However, it is worth considering that this slider is only an indicator that signals the card reader about the selected mode, and its position does not affect the card itself; in some card readers,
the write protection function may simply be absent - such devices will not "see" the position of the slider.
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.
