How to choose an SD card: which memory card is best for your smartphone and other devices? The best SD (SDXC) memory cards.

Consolidated testing of 20 SDHC memory cards with a volume of 32 GB

Now, no matter what store you go to, there are a huge number of memory cards from various manufacturers on the shelves. They differ from each other in format, class and, ultimately, in the speed of reading and writing data. But how big is the difference in practice? We will check this in our new testing!

If you format the card using the standard OS utilities or in a device that does not support the SDXC standard, it will have a different file system (for example, FAT32). The SD Association warns that this will cause the card to lose compatibility with SDXC devices. Fortunately, for some card readers, cameras, etc., a driver or firmware update is sufficient.

⇡ Increase in speed: fast, faster, even faster!

Along with the volume of memory cards, the speed of data transfer also grew. In the early days of SD, it was measured in multipliers or "speeds." One multiplier (or one "speed") was equal to 150 Kbytes / s - everything is like a CD in its time. It is only in such multipliers that the maximum access speed obtained under ideal conditions, be it reading or writing, is sometimes indicated - and this is not the best option for a buyer. Therefore, SD Associations decided to put an end to this disgrace, and in 2006 (SD Specifications V. 2.0), together with SDHC cards, four speed classes were approved for them: 0, 2, 4 and 6. Each class indicated the minimum data transfer rate in decimal megabytes per second - for both reading and writing. Except for the zero grade. It includes all cards issued before the adoption of the specified specification, regardless of performance. A unified standard for marking memory cards was also approved: the figure indicating the speed class was inscribed inside the capital letter C.

Speed ​​classes of memory cards

Alas, humanity is designed in such a way that it always lacks land, oil, minerals or the speed of memory cards. Therefore, in the next specification (SD Specifications V. 3.01 - in the same one that describes SDXC cards), the 10th speed class was presented, with a nominal 10 MB / s (again, in decimal format), and the UHS-I bus (Ultra High Speed ​​Version 1) that could be used with SDHC and SDXC cards. The use of this bus increases the maximum theoretical data transfer rate to 104 MB / s (in the case when this bus is supported by a card reader or other device) and does not entail any problems with backward compatibility between new cards and old readers (provided that the latter support SDHC or SDXC formats).

Memory cards that support the UHS bus are marked with the Roman numeral 1, and also the UHS bus speed markings - the numbers 1 or 3 inscribed in a capital U. UHS Class 1 is equivalent to the usual tenth SDHC speed class (10 MB / s ), and the third class of speed, as you might guess, should provide an access speed (sequential read and write) of at least 30 MB / s.

Then, in June 2011, SD specification version 4.0 appeared, describing the UHS-II bus, which should increase the maximum bandwidth up to 312 MB / s. In addition, the use of the UHS-II bus provides for an increase in contacts on the card by eight pieces. Separately, I would like to note the preservation of backward compatibility between UHS-II and UHS-I cards.

The Roman numeral II is used to label memory cards supporting the UHS-II bus.

At the time of this writing, 312 MB / s data transfer rates are still fantastic. And there are very few memory cards themselves that support the UHS-II bus, they cost like a good SSD drive, and of a larger volume. Take the Panasonic Micro P2 as an example: 32GB or 64GB, with a maximum sequential read speed of 2Gb / s. The price is about 11 or 16 thousand rubles, respectively.

UHS-II bus memory card

It turns out that over the 14 years of its existence, SD memory cards have undergone many changes and have been divided into several formats. But only readers, not cards, are backward compatible with previous formats (see diagram).

⇡ Options for marking memory cards. How not to make a mistake when buying?

Now let's briefly summarize everything that was said above. At the time of this writing, there may be two types of SD memory cards on sale: SDHC and SDXC. They differ from each other in maximum size and file system. SDHC has a maximum capacity of 32 GB and SDXC is 2 TB, although in reality it is very difficult to find an SDXC card with a capacity of more than 128 GB. We managed to find the biggest "largest" 256 GB card only from Lexar. It costs $ 399 in Amazon, but it has not been found in Russian stores.

Before proceeding to the further choice of a memory card, it is worth figuring out what capacity you need. If it is more than 32 GB, then you should go for SDXC and check all devices in which you plan to use this card for compatibility with this standard. You should especially carefully check old card readers and cameras, because modern equipment (if we are not talking about a laptop with Linux and a camera three years ago) should not have any problems with SDXC (or rather, with the exFAT file system). If your camera does not have SDXC support, then you should look on the Internet for a new firmware and a description for it - sometimes the manufacturer can add SDXC support in a new firmware. As, for example, it was done with the Pentax K-x camera.

So speed. In order to determine the approximate data transfer rate of a memory card, you need to look at its speed class and support for the UHS-I or UHS-II bus.

On some of the memory cards that took part in our summary testing, we also found not only the marking of the usual tenth grade, but also the speed indicated in the "multipliers" - this is a normal, albeit rare, phenomenon.

The best option would be a card that has an established write or read speed, as tested by the manufacturer, on the packaging or on the front side of which. Buying such memory, you can be sure that the sequential read or write speed will be higher than the minimum allowable level for the 10th grade. And for very expensive memory cards (for example, SanDisk Extreme Pro), the declared sequential read and write speeds on packages can reach values ​​of 90 MB / s. But in practice, memory cards with the specified speed are more expensive than others, which is quite normal - you have to pay separately for fast and tested memory. In addition, sometimes there are markings like "up to 60 MB / s" without specifying what type of data transfer this speed refers to - to read or write.

The picture below shows examples of speed class designations on memory cards. OltraMax card: just tenth grade; Transcend card: Grade 10 with UHS-I bus support and UHS speed grade 1; SanDisk: Grade 10, UHS-I, UHS-I Grade 1, and claims 95MB / s.

⇡ Test participants, specifications

Our consolidated testing involves 20 very different memory cards from various manufacturers - popular and not so popular. Among them there are both copies without the declared data transfer rate (but not lower than the 10th class), and cards with a data transfer rate of up to 90 MB / s. If the card's packaging indicated the speed, but did not say what it refers to (reading or writing), then so much the worse for a cunning manufacturer. In our table, we recorded this speed in the "read" and "write" cells with the mark "general".

Before proceeding to the description of our experimental subjects, I would like to remind you about the cost of memory cards. We have indicated two prices in the table. The first is the average retail value taken from 3DNews, and the second is obtained from other sources. Since the prices are average, the cards we have chosen in Moscow online stores can be found even cheaper than indicated in the table. Everything will depend on the total number of offers on the market, the relevance of a particular memory card and, quite likely, on the fluctuation of the dollar exchange rate over the past months.

⇡ Transcend Premium TS32GSDHC10, Premium 300x TS32GSDU1 and Ultimate 600x TS32GSDHC10U1

The trio from Transcend can serve as another illustration for the description of the marking of memory cards. On the youngest card (Premium TS32GSDHC10), only the 10th speed class is indicated, but on the other two (Premium 300x TS32GSDU1 and Ultimate 600x TS32GSDHC10U1), the 10th general and first class UHS are indicated, as well as the speed in "multipliers", which are almost equal to the speeds in MB / s indicated on the package. Something like this is done by manufacturers who want to make their cards more attractive to the buyer, because "300x" and "600x" at first glance look "larger" than 43.5 or 87.9 MB / s, respectively.

Although the fastest memory card, the Transcend Ultimate 600x TS32GSDHC10U1, has one advantage over the other test participants. The manufacturer stated that it uses MLC memory, while on the packaging (and in the specifications) of other cards it is not possible to find a word about the microcircuits used. However, the MLC (Multi-Level Cell) marking, by definition, can designate cells with both two and three (also called TLC) charge levels. Both options are used in memory cards.

⇡ Kingston Ultra SD10V / 32GB, Elite SD10G3 / 32GB and Ultimate SDA10 / 32GB

Kingston memory cards - another well-known drive manufacturer - will also be three in our testing. On the youngest card, Kingston SD10V / 32GB, only the tenth speed class is indicated, but for other cards, Kingston Elite SD10G3 / 32GB and Ultimate SDA10 / 32GB, read speeds of 30 and 60 MB / s are declared, respectively. For Kingston Ultimate and 35 MB / s, write speed is also stated.

⇡ SanDisk Ultra SDSDU-032G-U46, Extreme SDSDXS-032G-X46, and Extreme Pro SDSDXPA-032G-X46

SanDisk cards are a welcome exception in our test. And the thing is that all three cards of this company we use have the maximum access speed indicated. The youngest card, the SanDisk Ultra (SDSDU-032G-U46), has 30 MB / s sequential reads, while the SanDisk Extreme Pro has 95 and 90 MB / s sequential reads and writes, respectively.

⇡ ADATA ASDH32GCL10-R, ASDH32GUICL10-R and ASDH32GUI1CL10-R

ADATA is a manufacturer of storage devices of various types and purposes. The company's product line includes RAM, external hard drives, solid state drives and SD cards. It was the last three devices from ADATA that we took for the test.

Before us is an almost standard set of three cards: the simplest class 10 ADATA ASDH32GCL10-R without specifying access speeds and two more complicated cards. So, ADATA ASDH32GUICL10-R has a total speed of up to 30 MB / s, and the most pumped one, ADATA ASDH32GUI1CL10-R, has 95 MB / s for sequential reading and 45 MB / s for writing.

⇡ Silicon Power SP032GBSDH010V10, Elite SP032GBSDHAU1V10 and Superior SP032GBSDHCU1V10

Silicon Power can be called a direct competitor to ADATA, because on the official website of this company you can find almost the same range of products as on the website of the previous manufacturer.

The cheapest Silicon Power card - SP032GBSDH010V10 - only has speed class 10, while other models have speeds of 40 and 15 MB / s (Silicon Power Elite SP032GBSDHAU1V10), as well as 90/45 MB / s (Silicon Power Superior SP032GBSDHCU1V10) for reading and writing respectively.

⇡ OltraMax OM032GSDHC10, OM032GSDHC10UHS-1 and OM032GSDHC10UHS-1 95 MB / s *

OltraMax, unlike all other test participants, is practically unknown to the average consumer. But inside the packages of two fast OltraMax cards it is written that the company uses Samsung components, which is a good advertisement for the card manufacturer. The only pity is that in order to see such an advertisement, you have to buy a memory card and open the package.

The OltraMax trio is almost no different from the previous trios. The simplest and cheapest card from this manufacturer, OltraMax OM032GSDHC10, is designated only as 10th grade, the middle memory card, OltraMax OM032GSDHC10UHS-1, also cannot boast of any marks, except for 10th grade and UHS-I. But the coolest card, OltraMax OM032GSDHC10UHS-1 95 MB / s *, promises a speed of about 95 MB / s, which is very interesting.

⇡ Qumo QM32GSDHC10 and Toshiba FlashAir SD-F32AIR (BL8

The next two cards fall out of the general list a little. We received only one Class 10 drive from Qumo for testing. And Toshiba FlashAir SD-F32AIR (BL8 stands out for being able to provide access to content via Wi-Fi.

Memory cards with Wi-Fi are no longer considered something unusual or innovative - many manufacturers have such models, but their small variety hints at modest popularity. Judging by the characteristics, high speeds from Toshiba FlashAir SD-F32AIR (BL8 is not worth waiting for - this card does not even support the UHS-I memory bus. But it has Wi-Fi and even the ability to distribute wireless Internet, if you add a name to the card settings and password for access to another network

SD cards have a history of over 10 years. During this period, drives have changed several generations, increased the maximum amount of memory, increased speed and became commonplace for an ordinary user of technology. Let's see how SDHC memory cards differ from SDHC and SD. We will also figure out their characteristics and how to choose the right drive for your device.

SD drives are different from SDHC and SDXC.

SD stands for Secure Memory Card. This media type has been produced since 1999. Of course, today no one uses cards in their original form for obvious reasons. Over time, the creators began to increase the characteristics and volume, releasing new generations, which will be discussed below.

The main difference, as mentioned above, is spaciousness. However, devices also differ in read / write speed and support across devices (cameras, phones, and so on). There are 3 types in total:

• SD High Capacity;

Let's take a look at all the differences between SD, SDHC and SDXC memory cards separately.

Volume difference

The oldest and unclaimed type is MicroSD. The first generation holds only up to 2 GB of information (version 1.0) and up to 4 GB in version 1.1. These numbers are currently extremely small for the modern consumer, given the size of high-quality videos and photos that new smartphones and cameras produce. Such media can only be useful for transferring small files. There is no point in purchasing such a carrier on purpose. The file system is FAT16.

The second type is SDHC cards. They differ from ordinary SD in the increased amount of space and the file system. Now the maximum capacity is up to 32 GB, using the FAT32 file system.

The most recent type is SD eXtended Capacity. The standard was officially released in 2009 and remains in demand to this day. Compared to the previous generation, the SDXC standard, which differs in volume, can hold up to 2 TB of information. The file system is exFAT with support for FAT32 formatting.

Now you know the main difference between SDHC memory cards and SDXC memory cards, which you should pay attention to when choosing a drive for your device.

Supported by devices and operating systems

As of 2017, SD generation is supported by all devices that have a corresponding slot. All SD-only devices will not be able to read HC or XC media. Cameras and smartphones with SD eXtended Capacity are compatible with all three generations. There is no backward compatibility.

SD can also differ from High Capacity and eXtended Capacity in support of operating systems:

• due to exFAT, SDXC drives are not supported by the Windows XP operating system without installing a special update;
• MacBook and Mac OS have SD eXtended Capacity support since 2011;
• flagship Android devices support SD eXtended Capacity. For all other smartphones and tablets, you will need a special driver from Samsung.

Difference between Micro and Mini

Now let's figure out how MicroSD, MicroSDHC memory cards differ from their Mini counterparts. As you might guess, the main difference lies in the size. For compact technology, a Mini version has been created, which is usually supported in smartphones (it is customary to install it on the second SIM card slot). The difference between MicroSDHC, SDXC and SD is that they connect to a card reader without an adapter, while the Mini version requires an adapter.

Difference in speed

Now let's look at the differences between all SD, SDHC, SDXC memory cards in terms of information reading speed. Speed ​​classes are marked on the body of each drive: 2 (from 2 Mb / s), 4 (from 4 Mb / s), 6 (from 6 Mb / s), 10 (from 10 Mb / s). The designation of the classes indicates the minimum value of the write speed, therefore, in practice, the performance of a single drive may be higher. Manufacturers indicate characteristics in Mb / s, and not according to the established classification. Also SDHC and SDXC can support Ultra High Speed ​​technology (up to 25 Mb / s).

When choosing a drive, pay attention to its type and size. SDHC and SDXC are relevant today. Also, before purchasing, check the compatibility with the device for which the media is purchased to avoid incompatibilities.

Today, not a single user of mobile devices and other technology of the new generation can imagine their life without memory cards. Today, memory cards in MicroSD and MicroSDHC formats are very popular and in demand. Therefore, when choosing a card, one should know not only their distinctive features, but also general parameters, as well as the possibility of compatibility.

MicroSD Features

MicroSD memory card is the earliest format of such devices in the line of Secure Digital standards. Its emergence is a process of improvement and development of the previous MMS format. Such cards are most popular among users of personal computers, mobile phones, cameras and other modern gadgets.

A feature of these devices for storing information is:

• Small capacity not exceeding 2 GB.
• The standard size is 11x15 mm with a thickness of 1 mm.
• The maximum data exchange rate with the device, not exceeding 25Mb / s.

MicroSDHC Features

The microSDHC memory card is the result of further development, it is a direct descendant of the microSD card. Tellingly, MicroSDHC has similar overall parameters, but with a larger capacity, which reaches 32 GB. Also, such devices are characterized by a higher data exchange rate - 50-150 Mb / s.

Common features

As it has already become clear, both media are designed for installation and use in portable and mobile devices of the next generation. In 2000, the SD card was initially released, and then SDHC began to appear on the market.

The development of maps was carried out taking into account certain requirements related to data protection and security. Therefore, now the recording is carried out in a special box according to the protocol. In the future, it is inaccessible to the common user. To protect against unauthorized use, information on the new media can now be password protected.

Also, the developers have provided the ability to prevent the loss of information. The new SD media has a special switch “ lock", Which blocks the ability to write to it.

Naturally, all the parameters and characteristics of the MicroSD card were subsequently implemented in the new development of MicroSDHC.

An ordinary user should focus on one important point. As noted, the SDHC card is the result of an evolutionary process in the development of the original SD. However, it will not work with devices that were released for MicroSD. But older SD media can be easily combined with devices that are released with MicroSDHC support.

Another significant nuance that unites both types of memory cards is such a characteristic as Class... It shows the speed of writing to the device. In both cases, the class specified by the developer indicates the minimum speed at which data can be written to the card.

If such a medium is planned to be used as a device for storing information, then, in principle, the class indicator does not make much difference. This parameter loses its meaning, because usually the speed when moving data from a computer to a card does not make a significant difference and is not so important. For such purposes, you can purchase media even marked with class 2. There is no point in spending money for storage, and buying cards with an indicator above 4.

This parameter can be very important if it is planned to be installed in devices such as video recorder... This is where the minimum write speed plays a key role. Therefore, for use in such devices, you should purchase memory cards with a class of at least 10. Similar media may be required for modern smartphones, among the functions of which there is an opportunity to take pictures of very high quality.

The main difference between the two carriers is their volume... As already noted, the maximum volume with which a microSD can work is 4 GB, but at the same time MicroSDHC is of capacity up to 32 GB.

Now it is worth summarizing the information considered.

First, outline the common features for both memory cards:

• Both media are prototypes of the Secure Digital standard.
• Both memory cards have exactly the same purpose: storing information, recording and reading of which is possible with the help of many modern gadgets.
• The same overall dimensions: 11x15 with a thickness of 1 mm.

Differences between the two types of memory cards

Now it is worth highlighting the main differences between the two devices that are designed to store information:

1. MicroSD is also compatible with microSDHC card readers, which is not supported in SD gadgets.
2. Writing and reading information occurs at a speed not exceeding 25 Mb / s, while in SDHC this figure is 50-150 Mb / s.
3. MicroSD cards can be formatted in FAT12 and FAT16 systems, while SDHC cards can be formatted in FAT32.
4. The essential difference in the two types of memory cards is the volume: SD - up to 4 GB, while SDHC - up to 32 GB.

For most people, microSD is just a form factor, but it really isn't. You can easily insert any microSD card into a standard slot, but not all of them will work, since cards differ in many ways.

Format

There are three different SD formats in total, available in two form factors (SD and microSD):

• SD (microSD) - drives up to 2 GB, work with any equipment;
• SDHC (microSDHC) - drives from 2 to 32 GB, work on devices with support for SDHC and SDXC;
• SDXC (microSDXC) - drives from 32 GB to 2 TB (currently 512 GB maximum), only work on devices with SDXC support.

As you can see, they are not backward compatible. New format memory cards will not work on older hardware.

Volume

The manufacturer's declared support for microSDXC does not mean support for cards of this format with any size and depends on the specific device. For example, HTC One M9 works with microSDXC, but officially only supports cards up to and including 128GB.

One more important point is connected with the volume of storage devices. All microSDXC cards use the exFAT file system by default. Windows has been supporting it for over 10 years, in OS X it has appeared since version 10.6.5 (Snow Leopard), in Linux distributions exFAT support is implemented, but it does not work out of the box everywhere.

High speed UHS interface

I or II is added to the logo of the UHS-enabled card depending on the version

SDHC and SDXC cards can support Ultra High Speed, which, when supported by hardware on the device, provides higher speeds (UHS-I up to 104 MB / s and UHS-II up to 312 MB / s). UHS is backward compatible with earlier interfaces and can work with devices that do not support it, but at standard speeds (up to 25 MB / s).

2. Speed

Luca Lorenzelli / shutterstock.com

Classifying the write and read speed of microSD cards is as complex as their formats and compatibility. The specs allow four ways to describe the speed of the cards, and since manufacturers use all of them, a lot of confusion arises.

Speed ​​class

The speed class macro for ordinary cards is a number inscribed in the Latin letter C

The speed class is associated with the minimum write speed to the memory card in megabytes per second. There are four of them:

• Class 2- from 2 MB / s;
• Class 4- from 4 MB / s;
• Class 6- from 6 MB / s;
• Class 10- from 10 MB / s.

By analogy with the labeling of ordinary cards, the speed class of UHS cards fits into the Latin letter U

The cards operating on the high-speed UHS bus have only two speed classes so far:

• Class 1 (U1)- from 10 MB / s;
• Class 3 (U3)- from 30 MB / s.

Since the speed class designation uses the minimum record value, theoretically a second-class card may well be faster than a fourth-class card. Although, if this is the case, the manufacturer will most likely prefer to make this fact more explicit.

Maximum speed

The speed class is quite enough for comparing cards when choosing, but some manufacturers, in addition to it, use the maximum speed in MB / s in the description, and more often not even the write speed (which is always lower), but the read speed.

These are usually synthetic test results under ideal conditions that are unattainable with normal use. In practice, the speed depends on many factors, so you should not focus on this characteristic.

Speed ​​multiplier

Another classification option is a speed multiplier, similar to the one used to indicate the read and write speed of optical discs. There are more than ten of them, from 6x to 633x.

The 1x multiplier is 150 KB / s, that is, the speed of the simplest 6x cards is 900 KB / s. The fastest cards can have a multiplier of 633x, which is 95 MB / s.

3. Tasks

StepanPopov / shutterstock.com

Choose the right card based on specific tasks. The biggest and fastest is not always the best. For certain usage scenarios, volume and speed may be overkill.

When buying a card for a smartphone, volume plays a greater role than speed. The advantages of a large storage device are obvious, but the advantages of a high transfer speed on a smartphone are practically not felt, since large files are rarely written and read there (unless you have a smartphone with 4K video support).

Cameras that shoot HD and 4K video are a completely different matter: speed and volume are equally important here. For 4K video, camera manufacturers recommend using UHS U3 cards, for HD - regular Class 10 or at least Class 6.

For photos, many professionals prefer to use several smaller cards in order to minimize the risk of losing all images in case of force majeure. As for the speed, it all depends on the photo format. If you shoot in RAW, it makes sense to invest in a microSDHC or microSDXC class UHS U1 and U3, in which case they will fully reveal themselves.

4. Counterfeits

jcjgphotography / shutterstock.com

No matter how trite it may sound, buying a fake under the guise of original cards is now easier than ever. Several years ago, SanDisk claimed that a third of SanDisk memory cards on the market were counterfeit. It is unlikely that the situation has changed much since that time.

Common sense is enough to avoid disappointment when buying. Refrain from buying from untrustworthy sellers, and beware of offers of "original" cards that are significantly below the official price.

Attackers have learned to counterfeit packaging so well that sometimes it can be very difficult to distinguish it from the original. It is possible to judge with complete confidence about the authenticity of a particular card only after verification using special utilities:

• H2testw- for Windows;

If you have already faced the loss of important data due to a broken memory card for one reason or another, then when it comes to choosing, you will most likely prefer a more expensive card of a well-known brand than an affordable "no-name".

In addition to the greater reliability and safety of your data, with a branded card you will receive a high speed of work and a guarantee (in some cases even a lifetime).

Now you know everything you need to know about SD cards. As you can see, there are many questions that you will have to answer before purchasing the card. Perhaps the best idea is to have different cards for different needs. This way you can take full advantage of the equipment and not expose your budget to unnecessary expenses.

How to understand the class of the card, what is UHS and how to choose the best card at the lowest price.

We will tell you everything using examples of Toshiba SD cards. All data is relevant for CF and other types of cards.

The card always has the card type, baud rate, card class and bus specified.

Card types

There are three types of SD cards in total:

• SD- the very first memory cards, compatible with all devices. Capacities up to 2GB.
• SDHC - SD High Capacity- high-capacity cards. Capacity 4 - 32 GB.
• SDXC - SD Extended Capacity- extended capacity cards. Capacity 32 GB - 4 TB.

Speed

For photography, the recording speed with which the camera will save data is important.

On cards, the speed can be indicated directly, for example, 95 Mb / s.

You can also find cards in which the speed of work is indicated in multiples, for example, 600x. The multiplicity is always one x = 150 kb / s.

100x = 100 x 0.15 kbps = 15 Mbps. This speed dates back to CD-ROMs (things that were before the iPod and long before the iPhone). The maximum multiple speed is 633x (95 MB / s). For CF cards, the maximum multiple speed is 1066x (160 MB / s).

For example, Toshiba EXCERIA PRO UHS-II 16GB. Reading and writing speeds are 260 and 240 MB / s, respectively. This means that a gigabyte of data will be written to the card in 4 seconds. The main thing is that your camera supports such a speed and a bus (you will learn about it a little below).

Map class

The card class indicates the minimum guaranteed streaming write speed. For example, Class 10 corresponds to a speed of 10 Mb / s.

For video, it is not the peak rate that is important, but the streaming rate of the recording, otherwise there will be a loss of frames.

Since 2009, additional classes U1 and U3 have been introduced for SD cards (based on the new high-speed UHS bus). Classes provide a minimum speed of 10 and 30 Mb / s, respectively.

Example. Toshiba EXCERIA UHS-I. The card uses UHS speed class 3, which provides a minimum speed of 30 Mb / s. and although its maximum write and read speeds are 60 and 95 MB / s, this card is capable of recording 4K video.

Below is a table of correspondence between class and minimum stream recording speed.

SD has recently developed new standards for card classes that will enable 8K video capture.

What is UHS

UHS - (Ultra High Speed) ultra high speed bus that provides the fastest recording speed.

• UHS-I supports speeds up to 104MB / s
• UHS-II supports up to 312 MB / s.

UHS-II cards can be distinguished by their two rows of pins.

Example

As you can see here the speed is 260 Mb / s. Roman I stands for UHS-I class. And the U3 shows that the card supports 4K video.

Which card to choose

• Shooting FullHD video - cards Class 10, or class U1 of the EXCERIA series.
• Fastest Photo Write Speed ​​- Choose UHS-II cards with the EXCERIA PRO Series Fastest Speed.
• Shooting 4K video - EXCERIA U3 class cards.
• High speed recording + 4K video - EXCERIA PRO series U3 cards and UHS-II bus.