Which class of memory card is better to choose - an overview of SD formats. Choosing a memory card together Memory card slot main

Hi all! I think that many of you are interested in the question of which class of memory card is best to choose for a camera, video camera, tablet, mobile phone or some other digital device that uses an SD card to store information. Surely you know that there are several generations of SD cards with speed classification and memory capacity. So, each type of memory card has its own specification, which directly affects the scope of application and compatibility mode with a particular device.

Many consumers, when choosing a drive for their digital device, completely in vain ignore the classes of SD memory cards, taking into account only the type and large volume for storing information. IN Lately Manufacturers themselves clearly and clearly indicate in the specifications for the device what class of memory card is needed to work together with the device. However, some consumers still find it difficult to understand the types, classes, capacities and compatibility of SD drives. In this article I will try to talk as simply and in detail as possible about a digital memory card in SD format.

Let me start with the fact that the SD format has replaced the MMC portable flash memory card ( MultiMedia Card) with which they physically have the same size (32x24x2.1 mm), but technically have a different design. The format in question has its own controller and a special protected area from unauthorized access, as well as a manual switch to prevent unintentional erasure or overwriting of existing information. Keep in mind that accidental erasure protection is not activated by the SD card itself, but by the device in which it is located, provided that it supports this function.

Volume and format of SD memory card.

There are several types of memory cards in SD (Secure Digital Memory Card) format, which I have listed below in order of backward compatibility. That is, the previous memory card format in the list is backward compatible with the following ones and is not interchangeable in reverse order.

SD (Secure Digital Memory Card) is the very first secure digital memory card format. This type is compatible with all digital devices that support all of the following formats (SD, SDHC, SDXC).

• Maximum memory: 4 GB;
• Initial file system: FAT16.

SDHC (SD High Capacity) is the next high capacity SD memory card. This format works a little differently than the previous representative and is not backward compatible with devices that support the SD format.

• Maximum memory: 32 GB;
• Information exchange speed: 12.5 MB/s;
• Initial file system: FAT32.

SDXC (SD Extended Capacity)— another descendant of the SD memory card with extended capacity. This format has a different file system and is therefore not backward compatible with digital devices that only work with SD. Many devices released after 2010 should be compatible with this format. To finally make sure that the memory card is compatible with the device, look for the SDXC logo on the card and the device. In addition, a card reader capable of working with a format no higher than SDHC will not be compatible with SDXC cards. This format is not supported by all operating systems.

• Maximum memory capacity: 2 TB;
• Information exchange speed: 25 MB/s;
• Initial file system: exFAT.

SDHC I, SDXC I, SDHC II, SDXC II— a card with one of these logos has an increased data exchange speed due to improvements in the UHS bus interface. In simple and understandable language, we can say that UHS (Ultra High Speed) is an addition to the original SD format interface, which is improved by developers from time to time. It should be said that the host device will receive the maximum possible UHS speed only if both the memory card and the receiving device support UHS, otherwise they will be able to access the slower speed provided in the SD format.

• UHS I - has two architectures for the fastest data transfer of 50 MB/s and 104 MB/s. Here the developers have redefined the purpose of some pins to implement four-bit data exchange.
• UHS II - the next improved generation also has two architectures for high-speed data transfer of 156 MB/s and 312 MB/s. A four-bit data exchange mode is also used.

The maximum possible data transfer speed for the interface is indicated here, and you can find out the supported data transfer speed for a particular memory card from the specifications on the manufacturer’s website or from the information sticker on the card packaging. Full compatibility of UHS cards with digital devices that do not have the high-speed UHS protocol.

Since this SD format is aimed mainly at portable devices, it consists of three types. Each type of card has its own size.

For example, the standard SD format has a size of 32x24x2.1 mm, and miniSD has a size of 21.5x20x1.4 mm. The small microSD format has the most compact size of 11x15x1 mm, and with the help of special adapters this type of memory card can be adapted to the desired slot form factor.

Classes of SD memory cards.

Now let's take a look at what a memory card class means and what meaning this information carries for the consumer. So, under the classes there is information about the minimum write speed to the memory card. In other words, the higher the class of the memory card, the faster you can record and save voluminous information, play large audio and video files without interruptions and sound clips.

And to make it easier for consumers to navigate the speed capabilities of memory cards, the international SD Card Association classified them according to speed characteristics (multiplier) along with digital devices that can work with them, called SD Speed ​​Class. The speed on memory cards is indicated through a special multiplier called a rating.

This figure is constantly growing, but at the moment the SD card multiplier is from 6x to 633x. To make it clear, I will say that 1x = 150 KB/s. It turns out that entry-level cards have a speed of 6x = 900 KB/s, and SD cards top level comparable speeds are 633x = MB/s. According to the speed specification from the SD Card Association, all memory cards are divided according to the minimum recording speed characteristics as follows:

• SD Class 2: write speed of at least 2 MB/s - multiplier 13;
• SD Class 4: write speed of at least 4 MB/s - multiplier 26;
• SD Class 6: write speed of at least 6 MB/s - multiplier 40;
• SD Class 10: write speed of at least 10 MB/s - multiplier 66;
• SD Class 16: write speed of at least 16 MB/s - multiplier 106.

It is the class of the memory card that is one of the important parameters when choosing a removable SD drive. In a previous publication, I touched on the topic of unscrupulous manufacturers, and in this case the SD memory card was no exception.

Unfortunately, there are “honest” manufacturers who indicate a multiplier on the map that does not correspond to the actual speed. That is, the card may actually have the speed declared by the manufacturer, but in read mode and not write mode.

To determine the multiplier of an SD memory card, you can conduct your own independent test using a card reader and a specialized program (for example, for Windows - H2testw; Linux - F3), and then compare the results with the table. You can also see how we did it, which can also be used to test SD and MMC cards.

Rating/Multiplier (X)	Speed ​​(MB/s)	SDHC class
6x	0,9	n/a
13x	2,0	2
26x	4,0	4
32x	4,8	5
40x	6,0	6
66x	10,0	10
100x	15,0	15
133x	20,0	20
150x	22,5	22
200x	30,0	30
266x	40,0	40
300x	45,0	45
400x	60,0	60
600x	90,0	90

The speed class rating plays an important role for HD video mode, because in this case the digital device is in a state of constantly saving a stream of data to the memory card. It is the resolution and format that influence the number of stable data streams. Therefore, be sure to check the instructions for the digital device for the minimum speed class requirements for HD video mode.

How to choose an SD card.

As a rule, the speed class of a memory card on a simple SD format nameplate is indicated by a number inside the letter C, and for the UHS standard, the speed class is indicated by a number inside the letter U. Scope of application of the classes and compatibility with devices.

Class	Write speed	Purpose
Class 2	at least 2 MB/s	Recording video data for standard definition television in SD format
Class 4	at least 4 MB/s	For recording HD (high definition) video, as well as Full HD (high resolution from 720p to 1080p/1080i). Entry-level digital cameras, gaming consoles and other devices that support SDHC cards.
Class 6	at least 6 MB/s
Class 10	at least 10 MB/s	For Full HD (1080p) video recording and sequential recording of HD stills (high-speed data bus)
UHS Speed ​​Class 1 (U1)	at least 10 MB/s	Capture Full HD video, 3D video, High Definition (HD) photos, and real-time broadcast recording
UHS Speed ​​Class 3 (U3)	at least 30 MB/s	Recording video files for 4K television - UHD television (UHS bus). D-SLR and D-SLM cameras and video cameras with 4K or 2K support.

And finally, I’ll say a few more words about the SD card compatibility mode. SDHC memory cards are not compatible with those digital devices that are originally designed only to work with SD cards, but those host devices (camera, video camera, phone...) that can work with SDHC cards are fully compatible with SD cards.

SDXC format memory cards should only be used with SDXC devices, as they will not work with SD / SDHC devices, but digital SDXC devices can use and support SD, SDHC and SDXC memory cards. SDHC host devices support both SD and SDHC memory cards, and SDHC memory cards can be used with SDHC and SDXC digital devices.

I hope I was able to tell you about something complicated in a simple way and you can now choose an SD card for your camera, video camera, phone, tablet, reader, and so on. Subscribe to new articles, there will be a lot of interesting things ahead. If you can add to the material or express your opinion, then by all means do so in the comments.

2020-02-18T16:47:02+00:00

There are trash cans in the yard for Prestigio tablets.

2019-09-18T23:37:08+00:00

I recently bought a Samsung 256GB card for 15 bucks on Ali at a promotion... It arrived without packaging, just an adapter and a card in a box. The writing speed of large files is 10 Mbit/s, the software shows 22 Mbit/s writing, reading and here and there 4-5 Mbit/s. h2testw uploaded 238GB of files and read them, the whole procedure took about 20 hours. And it’s not clear, it seems like the capacity is real, but the speed is clearly not like U3? How else can you check whether it is fake or not?

2019-07-04T12:46:10+00:00

You should write the model of your tablet so that you can find out... Perhaps the manufacturer made a mistake, and not the author of the post.

2018-04-22T16:47:00+00:00

Sony usually uses MemoryStick cards

2017-06-01T22:14:44+00:00

Hello! please help me choose a memory card for the Prestigio MultiPad PMP5080CPRO tablet

2017-05-16T13:08:47+00:00

Is a memory card labeled “for action camera” suitable for a smartphone? For recording videos and photos

2017-05-10T10:19:35+00:00

Hello. I have an old Sony Cyber-Shot DSC-W570 camera (2011). I would like to buy a 64 GB memory card. Our store has several attractive offers for SD cards with U1 class. But will such a class work on an old camera? Or look for grade 10 (C10)?

2017-05-01T14:35:35+00:00

Everything is relative. A quality item cannot be cheap. And sellers really sometimes surprise with their prices.

2017-05-01T10:18:41+00:00

The price of a memory card depends only on the arrogance of the seller! and not on quality! It is necessary to be able to check its quality on a computer using the h2testw program - this will be very reliable! There should also be a guarantee for the flash drive or a refund like on the aliexpress website. By the way, if you don’t want to overpay and buy cheaper than the sellers in your stores buy, use the function of returning the cost of purchases from the aliexpress website. Important! Read reviews before purchasing products on Ali!

2017-04-21T17:49:35+00:00

Which one and why? Do you think this will be more logical and convenient? P.S. The opinions of visitors are important to me.

2017-04-21T17:28:31+00:00

Place the table at the beginning of the article

2017-03-12T23:46:18+00:00

Please tell me what's the matter? I bought several different ones micro SD card for testing. The test is as follows: Turn off and turn on the MP3 player - only with the KingMax card the volume level and approximate position of the track are saved. The remaining cards are reset to the beginning and to the minimum volume - very inconvenient! How is KingMax different from others? The capacity is the same 2GB, the class is not indicated on any card.

2017-01-31T14:06:24+00:00

I've already seen a card with a multiplier of 1833x 275Mb/sec)) And if anyone plans to record 4K video, 64GB is not enough for an SD card, it gets clogged up pretty quickly))

2017-01-07T06:29:51+00:00

Cards with a capacity of 64 and higher come from the factory formatted in exFAT. Not all devices understand this format, so it didn’t work on the tablet initially. After reformatting to fat32 and ext4 (why ext4? Do you have an infinite number of rewrite cycles to keep a journaled FS on a flash drive? in this case - only ext2, only speed at the expense of excessive reliability) exFAT was screwed up and the device saw the familiar FS.

2016-10-27T18:18:28+00:00

The question is why the manufacturer writes that the tablet supports microSDHC cards up to 128 GB, although you write that this type of card has a capacity of up to 32 GB

2016-10-06T08:58:57+00:00

The record memory card is designed primarily for shooting 4K and 8K high-definition video, as well as panoramic videos, the files of which take up a lot of space. The world's first memory card with a capacity of 1 terabyte was released by SanDisk, but for now it remains a prototype. I think that soon it will be available in online stores.

2016-07-24T16:51:26+00:00

What kind of program can you tell me?

2016-06-26T18:01:02+00:00

View technical specifications. If you want help, please indicate your device model.

2016-06-25T10:07:37+00:00

Of course, I understand everything, but how can I find out what sizes of SD cards my smartphone supports?

2016-06-02T14:44:38+00:00

Hello! I bought a lumia 640 xl. What card do you recommend buying?

2016-04-04T11:37:48+00:00

Absolutely right... The class of the card affects the read and write speed. But before choosing an SD card, you should find out what maximum capacity your device supports.

2016-04-04T08:35:19+00:00

I managed to stuff first a smartphone, then an incompatible micro sd into the tablet! This is done very simply: I have a 64 GB card, class 10. Didn't work upon initial installation. Using a program (there is one), I divided Fat 32 and ext 4 into two sections. I inserted it and it worked! Then I rooted the device. I changed the USB drive from micro sd. So the cards don’t work not because of the class, but because of the volume!

2016-03-31T11:38:22+00:00

Good afternoon Samsung Galaxy 5 phone. I bought a micro sd 64 GB. put!!! I download it to my phone via utorrent. It downloads to the internal memory of the phone at a speed of 10 mbs, but on micro sd it doesn’t go above 1.5!! What can you do to download files quickly to the micro sd!!! Thank you!

2016-03-31T02:34:27+00:00

Which card is better CDXC or memory stik from SONY?

2016-03-16T10:06:17+00:00

Thank you for the article! Very informative, structured and simply written!

2016-03-04T12:20:48+00:00

Good afternoon Thank you for the article. Useful. In the article, write how to choose a card. I have a question. Let’s simulate the situation: if you have a smartphone that records or plays video from the card at a speed of 4 Mb/s, then there is no point in buying a class 6 CD card. Question: how can you determine the video transfer speed before purchasing a card? Thank you for your attention.

Several speed tests budget cards 32GB MicroSDHC memory, using CrystalDiskMark utility and internal PCIe card reader Realtek RTS5227-GR & RTS5249-GR laptop MSI GE70 0ND-082X.
MicroSDHC memory card: . Photo of packaging included with microSD - SD adapter:

Card capacity: 32GB. Classification by recording speed: Class 10. MicroSDHC memory card is made for high-speed continuous shooting. Designed for use in mobile phones, smartphones, communicators, PDAs, MP3 / MP4 players, in digital cameras and video cameras, in other digital devices.

Using the CrystalDiskMark 5.0.2 x64 test, we will check the speed of the Silicon Power SP032GBSTH010V10-SP.

MicroSDHC memory card: . On the package there is an inscription: read speed - up to 48Mb/s (320x), write speed is lower. Specifications shown are based on internal testing and performance may be lower than stated depending on the host device, interface, operating conditions and other factors.
Waterproof, immune to x-rays, magnetic fields and extreme temperatures, shockproof.
Speed ​​class: UHS-I.
Performance Class 10 is ideal for continuous Full HD video shooting.
Made in Malaysia. The adapter is made in China.
Warranty: 60 months.

Take and store more photos High Quality and video in Full HD format on a smartphone or Android tablet using a SanDisk Ultra microSDHC UHS-I memory card. And the SanDisk Memory Zone app, available on the Google Play Store, is a convenient way to view, access and back up all the files in your phone's memory. The application can be configured to automatically upload files from the built-in storage to the memory card, which will help your smartphone work at maximum performance.

The SanDisk SDSDQUAN-032G-G4A memory card showed the highest sequential read and write speeds: 30MB/s.

Map microSD memory Transcend's Class 10 HC offers excellent performance in just 1/10 the size of an SD card. Transcend TS32GUSDHC10 features extraordinary Class 10 speeds introduced by the SD Card Association as new SD 3.0 specifications, with 10MB/s write speeds guaranteed. A class 10 microSDHC card with high speed characteristics, a large memory size of 32GB with a minimum size is especially recommended for use in modern mobile devices.
Fully compatible with SD 3.0 standard.
Class 10 guarantees fast data transfer.
Data transfer speed of at least 10Mb/s, read speed up to 20Mb/s.
Built-in ECC technology to detect and correct data transmission errors. Exclusive RecoveRx program for recovering deleted and lost data from portable media.
Extreme protection. To guarantee maximum level performance and reliability, Transcend tests its microSD memory cards under the most severe operating conditions.
Waterproof: Meets JIS IPX7 standard and remains functional even after being submerged in water up to 1m deep for 30 minutes.
Reliable even in extreme temperatures: withstands both extremely low (down to -25C) and high (up to 85C) temperatures.
ESD protected: They are resistant to static charges as they are designed to meet EMC IEC61000-4-2 standards.
X-ray protection: Complies with ISO7816-1 standard and is not affected by airport X-ray scanners.
Impact resistance: they are distinguished by excellent impact resistance, vibration resistance, and high bending and torsional rigidity of the body.
Dimensions: 11 x 15 x 1 mm.
Supply voltage: 2.7V~3.6V.
Operating temperature range: -25C(-13F) to ~85C(185F).
Resource: 10K connection and disconnection cycles.
Weight: 0.4 grams.
Made in Taiwan.

The utility showed sequential read speeds claimed to be up to 20MB/s (133x), the same as the SanDisk SDSDQUAN-032G-G4A card: 30MB/s.

(or SDC10G2/32GBSP without SD adapter included). Kingston's microSDHC/microSDXC Class 10 UHS-I memory card features Class 10 UHS-I speeds (45MB/s read, 10MB/s write), making it ideal for photographers who capture everything from still images to children's images. or animals in motion. It's also ideal for capturing cinematic-quality HD (1080p) video and has faster buffering times between shots than Class 4 memory cards.
The smallest microSDHC/microSDXC Class 10 UHS-I SD memory card is a popular solution for expanding the memory capacity of tablets, smartphones and action cameras. It can also be used in conjunction with an optional SD memory card adapter for standard size SDHC/SDXC host devices.
This universal card The memory is designed to withstand extreme conditions and is tested to be waterproof, temperature proof, shock proof, vibration proof and X-ray proof. With a wide range of capacities (from 8GB to 128GB), you can choose the right memory card for your needs and have free space to save thousands of high-quality photos and hours of video.
- Class 10 UHS-I speed (45MB/s read, 10MB/s write). UHS-I interface - microSDHC/microSDXC Class 10 UHS-I is ideal for shooting cinematic HD video (1080p) and photos in motion (children, animals, etc.)
- Compact form factor.
- Reliable protection of photos and videos even in extreme conditions.
- Capacity 8GB–128GB. To meet the needs of users, Kingston microSDHC and microSDXC memory cards have capacities ranging from 8GB to 128GB.
- Plus, all Kingston memory cards come with a lifetime warranty, free technical support and feature legendary Kingston reliability.
- FAT32 format (microSDHC 8GB–32GB); exFAT (microSDXC 64GB–128GB).
- Operating temperatures: from -25 to 85C.
- Operating voltage: 3.3V.
The SD Card Association defines card speeds in two terms: Speed ​​Class and UHS Speed ​​Class.
- Speed ​​Class is a number that determines the speed of the memory card; 4 means 4MB/s, 6 means 6MB/s, etc.
- UHS (Ultra High Speed) uses minimum write speeds to differentiate between memory cards; UHS-I Speed ​​Class 1 has a minimum write speed of 10MB/s, and UHS-I Speed ​​Class 3 has a minimum write speed of 30MB/s.

Photo of the back side of the packaging of the Kingston SDC10G2/32GB memory card.

The CrystalDiskMark utility showed a consistent read speed of 81 MB/s, which is higher than the stated 45 MB/s, but the write speed is one of the lowest: 17 MB/s (but also higher than the stated 10 MB/s).

Designed for 4K and Full HD video recording, and provides shockproof, waterproof, and X-ray protection.
Record all the most interesting things on your smartphone or digital camera. With a 32 GB memory card, you'll have enough space for all your photos and videos in Full-HD format, so you can take your precious memories with you always.
The EXCERIA microSD M302 memory card is a real find for sophisticated photographers. Huge capacity and ultra-high recording speed allow you to save data in Full HD format.
Toshiba M302 microSD memory cards fully comply with the requirements of the SD Association. The Toshiba ADP-HS02 adapter provides compatibility with SD and SDHC slots.
Toshiba's write-protect feature prevents accidental overwriting.
Designed to Toshiba's highest quality standards, SD memory cards come with a standard 5-year limited warranty.
UHS-I microSDHC memory card supporting speed class: Class 10, UHS Speed ​​Class 3 (minimum write speed: 30MB/s). Claimed sequential read speed: up to 90MB/s. Approximate usable capacity: 28.8 Gb/s.

The CrystalDiskMark utility showed sequential read speed: 86.96 MB/s, which is slightly short of the stated 90 MB/s, write speed: 26.82 MB/s.

MicroSDHC memory card: .
This memory card is rated Speed ​​Class 10 for video quality, which means you can shoot in Full HD without losing frames. And with up to 64GB of memory, you can save plenty of Full HD video files before you need to transfer them to your computer.
Waterproof, shockproof, heat-resistant and X-ray resistant, SanDisk Ultra microSD UHS-I cards keep your memories protected from the elements. You can safely use your phone or tablet during snowfall, shoot at the edge of the pool or among the hot sands of the desert. A SanDisk memory card will survive even if the device itself fails.

SanDisk Ultra microSD UHS-I cards are the ideal companion for powerful Android smartphones and tablets. With additional memory on the card, you can take more photos and videos without worrying about available space.

The CrystalDiskMark utility showed sequential read speed: 43.4 MB/s, which is slightly short of the stated 48 MB/s, write speed: 37.8 MB/s.

MicroSDHC memory card: .
The EVO Plus series cards are ideal for recording life's most precious moments and then enjoying 4K UHD video on a compatible device.
Micro SD cards are compatible with a wide range of devices, and the included SD adapter makes it suitable for even more more devices from almost any brand, while maintaining the excellent speed and performance of EVO Plus.
EVO Plus cards come with four types of protection: they can withstand up to 72 hours in seawater, extreme temperatures, airport X-ray machines or exposure to electromagnetic waves equivalent to an MRI.

Speed ​​class: Grade 1, Class 10. UHS-1 interface. Data transfer speed (read/write): 95/20 MB/s.

CrystalDiskMark showed a sequential read speed of 29.88MB/s and a sequential write speed of 27.02MB/s. The thing is that the memory card was inserted into the card reader of a budget laptop ASUS X554LJ (90NB08I8-M06800) which uses a USB 2.0 interface with a bandwidth of 480 Mbit/s.

The owner of any gadget sooner or later has a desire to increase its memory. Fortunately, most often this is possible thanks to memory cards. Tablets, smartphones, e-readers, video cameras, cameras are not a complete list of devices, most models of which have a slot for a memory card.

A memory card may be needed not only to increase the memory capacity of the device - in some cases, copying a file to a memory card is the fastest and in a simple way exchange information with other devices.

The algorithm for choosing a memory card for specific equipment is clear and seemingly quite simple:

1. Decide on the form factor of the memory cards.

2. Determine the minimum speed required for the gadget to operate.

3. Select the memory capacity of the card based on your needs and financial capabilities.

Unfortunately, in reality everything may not be so simple, because the speed of the card can be described by as many as four different parameters. Therefore, before you start choosing a memory card, you should figure out what each parameter is responsible for.

Characteristics of memory cards

Form factor(card standard that describes its size, number, location and purpose of pins) is primarily determined by the gadget in which the card is supposed to be installed. There is usually a marking next to the memory card slot indicating which cards the slot is intended for. Well, of course, full list Supported memory cards will be listed in the gadget's instruction manual.

There are many form factors of memory cards, but the most common today are:

MicroSD/microSDHC/microSDXC;

JetDrive lite;

Compact Flash:

microSD/microSDHC/microSDXC And SD/SDHC/SDXC belong to one type of card – Secure Digital. They are presented in three formats (SD, SDHC, SDXC) and three form factors (SD, miniSD, microSD), although miniSD is practically not found today. SD cards of the same format and different form factors differ only in size, they have the same filling - many cards of the microSD form factor even come with an adapter that allows them to be used as SD form factor cards.

The formats differ in the possible maximum volume:

SD can have a capacity of up to 2 GB;

SDHC – up to 32 GB;

SDXC – up to 2 TB (currently the maximum capacity among cards produced is 1 TB; on sale there are capacities of up to 512 GB).

The formats are compatible from top to bottom, i.e., a device that supports SDHC cards will also support SD, but SDXC cards will not work on this device.

JetDrive Lite can also be classified as SD format. The JetDrive Lite card is an SD card with slightly different dimensions - it is shorter than the original one. The size of the card has been changed so that when installed in MacBook Air and MacBook Pro, it does not protrude beyond the dimensions of the laptop.

The card reader depth varies between MacBook models, so JetDrive Lite cards also come in different sizes:

Memory Stick is a memory card used in Sony devices; now the most common type is Memory Stick PRO Duo ( MS Pro Duo). The characteristics are similar to the SDHC format, but have a much higher price. Fortunately, in most cases, instead of an MS Pro Duo card, you can use microSD cards with an appropriate adapter.

Compact Flash- an old-timer among modern memory cards, produced since 1994. Despite such a respectable age, CompactFlash cards are still popular in video and photographic equipment due to their high write/read speed and large capacity: the latest edition of the standard limits the speed to 167 MB/s, and volume – a completely unrealistic 128 Petabytes. In addition, the card data exchange standard (ATA) does not change, and in cameras fifteen years ago you can use modern maps(if the volume is supported), as well as vice versa - insert ancient CF cards into modern cameras (if they are “fast enough”).

XQD– the memory card format developed by SanDisk, Sony and Nikon is intended for devices that are particularly demanding in terms of write/read speed. Today it is considered the most promising format for modern high-resolution video and photo cameras.

Speed ​​class memory card determines its speed performance. Most often, you can find out the minimum recording speed from the class - this indicator is very important for cards on which real-time video is recorded. Speed ​​class mismatch can result in frame loss and recording errors. There are several speed class designation standards.

SD (microSD) cards have four speed levels Class2, Class4, Class6 And Class10. The class is indicated by a number inside the letter “C” and corresponds to the minimum write speed (in MB/s) - for a Class6 card the minimum write speed will be 6 MB/s.

SDHC and SDXC cards can support the UHS (Ultra High Speed) protocol. UHS speed class is indicated inside the letter “U” and corresponds to the minimum write speed in tens of MB/s. A card with a UHS U3 speed class will have a minimum write speed of 30 MB/s. There are also speed specifications for Video Speed ​​Class - (the minimum speed in MB/s is indicated after the letter "V") and Application Performance Class, indicated by the letter "A" and has a minimum write speed of 10 MB/s.

The latest modification of SDHC / SDXC cards with support for the UHS-II protocol has an additional row of contacts on the body and read/write speeds of up to 300 MB/s. But such cards have not yet received wide distribution.

Cards MS PRO DUO provide a minimum write speed of 4 MB/s.

Cards JetDrive Lite provide a minimum write speed of 60 MB/s.

Cards XQD provide a minimum write speed of 125 MB/s.

When choosing a memory class, you should focus on the requirements of the device for which you are purchasing the memory card. If, for example, the device does not support the UHS protocol, there is no point in buying a card with the U3 class - it will not work faster than C10. If the card is intended to be used in various devices, when choosing a speed class, you can refer to the following table:

Since read speed is usually much faster than write speed, manufacturers sometimes indicate the read speed class as multiplier(similar to CD-ROM speeds), with 1x = 150 KB/s. That is, a card with a speed of 133x will have a read speed of 133*150/1024 ≈ 20 MB/s, and a 1067x card will have a read speed of 156 MB/s.

Often manufacturers also indicate maximum values write speed And reading– they can be many times greater than the corresponding values ​​obtained by the speed class of the card. But it should be understood that such speeds are achieved under ideal conditions; in reality, the speed will always be lower, sometimes by several times. Therefore, when choosing a card, you should be guided by the minimum recording speed, and take other speeds as additional information.

Card volume determines how much information will fit on it. On the one hand, the more memory, the better. On the other hand, larger capacity cards are more expensive. In addition, the maximum capacity of memory cards on many devices is limited to a value less than the maximum capacity of a card of a given format. A device, for example, may support SDXC cards, but have a maximum memory card capacity of 128 GB. There is no point in buying a 256 GB SDXC card for such a device. Such subtleties should be clarified before purchasing in the device’s instruction manual.

Memory card options

If you need to increase the memory of your smartphone by 2-8 GB, first of all you should make sure that it has this option. If there is a memory card slot, most likely it is designed for microSD cards. An inexpensive microSD card of speed class 2-4 is suitable for a smartphone.

Most e-readers support cards up to 32GB. A card of this size and speed class 4 will allow you to assemble an impressive library at an affordable price. You just need to decide on the form factor: SD or microSD.

Progress does not stand still; some modern smartphones can record video in FullHD quality. To prevent video quality from deteriorating during recording, it is better to choose a card with a higher class: 6-10.

For action cameras recording in FullHD format, the best option would be a speed class 10 (or U1) card with a capacity of 16-32 GB.

If you are going to use the card as a hard drive for a tablet or laptop, choose from high-speed SD or microSD cards with a capacity of 128 GB or more.

To increase the memory capacity of a MacBook Air or MacBook Pro (up to the 4th generation), you can use a special development for Apple laptops - JetDrive Lite cards. Check the specific type of card in accordance with your laptop model using the table given in the guide.

If you're a professional photographer who often shoots bursts in RAW format, you'll need a high-speed card. CompactFlash or XQD - depends on the model of your camera.

With this article, our website continues a whole series of useful materials, the purpose of which is to make it easier to choose any product from the thousands of options offered on the market. Agree, choosing a specific model of a device always takes a lot of time, which can be spent usefully. In today's material we will talk about choosing a memory card for a smartphone, tablet or camera.

Introduction

Flash memory is used today in almost all electronic devices - both in personal computers and laptops in the form of SSD drives, and in mobile devices - in the form internal memory and flash cards. The latter will be discussed in this article. By using small map(their sizes have long allowed them to be used in the most compact and thin devices) you can increase the available memory of a smartphone, camera or tablet by many gigabytes, so you can carry more content with you - games, music, videos or books and magazines. In addition, the cost of high-capacity and fast memory cards today is lower than ever.

Memory cards are not as fast as USB flash drives, but their speeds have long reached a level that allows you to easily record 4K video on them, much less view it. But different card models can vary greatly in their data writing and reading speeds - you will learn about this in the section dedicated to their characteristics. But it is worth noting that different devices can support cards of a certain maximum capacity - for example, cheap smartphones sometimes cannot work with microSD cards with a capacity of more than 32 GB. Also, don't expect new speed gains from an old camera by using a card with a higher speed class - it's likely that the card will run in a slower mode to ensure compatibility. To find out about support for specific speeds and memory card sizes, you need to refer to the official user manual of a particular device.

By 2015, the memory card industry had focused on just two types - SD and microSD. The former are more often used in photo and video cameras, sometimes in laptops; the latter are more often used with smartphones and tablets. Once upon a time there were many more types of cards - some of you may probably remember names like MMC, Memory Stick Duo or xD-Picture. Fortunately, this fragmentation is now gone - almost any device supports either SD or microSD cards (or even both formats). We will talk about their differences, as well as other important characteristics below.

Main characteristics of memory cards

As we already reported in the introduction, now almost the entire memory card market is occupied by models of two types - microSD. They are used in all possible electronic devices: cameras, smartphones, tablets, e-readers, GPS navigators and even some game consoles.

SD and microSD cards are divided into four generations. SD 1.0 generation cards supported volumes from 8 MB to 2 GB, SD 1.1 generation cards - up to 4 GB, SDHC - up to 32 GB, SDXC (the most advanced and expensive) - up to 2 TB. SDHC and SDXC cards cannot be used with SD 1.0 / SD 1.1 devices.

The main thing to remember is that a device that can handle a newer SD card standard will be able to handle older cards, but most likely not the other way around (more on this below).

Memory capacity, GB

Memory cards with a capacity of less than 16 GB are hardly worth buying - their cost has already dropped to a very low level, and 16 GB is not so much for high-quality photos and videos. If you plan to get serious about photography or video shooting, you'll probably want to use a card with at least 32GB of memory, or better yet, 128GB. If you just want to increase the memory of your smartphone, then 32 GB will be quite enough in most cases.

Data writing and reading speed

The write speed of a memory card may be a very important parameter for you. The fact is that when taking photos and videos, cameras transfer the received data to the internal memory buffer, and from there the photos and videos are transferred to the card’s memory. If this buffer fills faster than the data can be written to the card (for example, when shooting in burst mode, when the camera takes a series of high-quality images), then it will simply be lost.

Read speed is not that important, but the higher it is, the faster you can work with the data that is recorded on the card. For example, if you want to watch high bitrate video on your tablet in FullHD or higher resolution, then you will need a pretty good card.

You can see examples of maximum and satisfactory card speeds below - in the " 10 best SD and microSD cards".

UHS interface support

UHS is a faster interface that is supported more expensive cards memory standards SD and microSD. UHS-I allows you to transfer information at a speed of 50 MB/s or 104 MB/s, and UHS-II - at a speed of 156 MB/s or 312 MB/s.

Speed ​​class

A designation of the form "Class x" or "Ux", which indicates the minimum standardized data transfer rate of a particular card. Memory cards can have the following speed classes:

• Class 2 - at least 2 MB/s, you can record SD video.
• Class 4 - at least 4 MB/s, you can record HD video or FullHD video.
• Class 6 - at least 6 MB/s, you can record HD video or FullHD video.
• Class 10 - at least 10 MB/s, high-quality FullHD video recording.
• UHS Speed ​​Class 1 (U1) - at least 10 MB/s, high-quality FullHD video recording.
• UHS Speed ​​Class 3 (U3) - at least 30 MB/s, video recording in resolution up to 4K.

In addition, manufacturers often designate the speed of their memory cards with a multiplier such as "100x" or "600x" in the name. Several of these multipliers correspond to speed classes (13x - Class 2, 26x - Class 4, 40x - Class 6, 66x - Class 10), and the fastest cards currently have a 633x multiplier and can transfer data at speeds of up to 95 MB/s .

Adapters included

Special adapters may be supplied with the memory card for use in devices that do not support its original type. In most cases, this is an SD adapter for microSD cards - a plastic housing for a microSD card that allows you to insert it into a slot for SD cards, which are much larger. If you plan to use one card on several devices that support different types, then the included adapter will definitely not hurt.

USB card reader included

You can transfer captured photo and video files to a PC not only by connecting the camera itself - it is much more convenient and sometimes faster to use a special card reader that is inserted into the USB port of the computer. The presence of such a card reader in the kit is very nice bonus, which usually doesn't cost too much.

10 best SD and microSD cards

An SD card that will do an excellent job of recording high-quality FullHD video and taking large photos in burst mode. Those who record 4K video will want to use models that are recommended by their camera manufacturer.

A cheaper SD model, which should also do an excellent job of recording FullHD video and taking high-quality photos.

A very high-speed and quite expensive SD model that can easily cope with recording 4K video and has a large enough capacity for its temporary storage.

A slightly faster SD card than the first two models on this list. It also does an excellent job of recording FullHD video and has twice the capacity.

There are a large number of differences and specifications that it is advisable for the user to understand when purchasing a suitable SD card. In addition to considering the speed parameter, it remains equally important bus interface type. What is she like?
Bus is a way to establish communication between card components (internal and external), communication with the central processor and main memory.

In the case of regular SD devices, an interface called High Speed, which is preceded by Default Speed ​​Device. Nevertheless SDHC cards and SDXC are designed for much higher memory capacities than SDSC.

Modern devices are equipped with high-quality cameras capable of recording video material in HD, Full HD and 4K resolution. Along with the development of such devices, memory cards with an average speed of at least 25 MB/s cannot remain aside. Even in some cases they can be called slow.

New and fast bus interface UHS, or Ultra High Speed, was created specifically for high-bandwidth SD cards.

Who determines the development and standards of SD cards

There is a non-profit organization called the SD Association that is responsible for maintaining the quality standard SD(Secure Digital) for external storage media. It was created in 1999 as a result of joint efforts of companies such as SanDisk, Panasonic and Toshiba. The standard introduced for SD cards was borrowed from another known as MultiMediaCard or MMC for short.

What is a UHS-I SD card

Ultra High Speed ​​Phase-I(UHS-I) is the first iteration of the Ultra High Speed ​​interface built for SD cards, which was first introduced in 2010.

UHS-I supports a theoretical maximum bus speed of 104 MB/s. Do not confuse the bus speed with the actual speed of reading or writing data. The reason for this is the large number of possible factors that can slow down performance.

SD specifications version 3.01 define different bus modes for UHS-I. They allow 4-bit data transfer at different clock speeds and frequencies of the SD card bus itself.

Interface types

Bus speed

Voltage

For the SDR104 (Single Data Rate) mode, the clock frequency is set to 208 MHz and the bus speed is 104 MB/s. In the case of DDR (Dual Data Rate), the signal is transmitted in only half a clock cycle. Thus, the write and read speed is twice as fast. For example, a 50 MHz clock allows an SD card to operate at 50 MB/s.

According to the specification, UHS-I is compatible with two types of cards: UHS50 and UHS104. The device to which the card is connected must support various operating modes in order to work as efficiently as possible with its speed potential.

For example, if the host supports SDR104 mode, it is capable of processing the card at a speed of 104 MB/s and its model must be UHS104.

Don't forget about backward compatibility. UHS SD card can work on a host device that certainly supports the UHS bus.

What is a UHS-II SD card

Ultra High Speed ​​Phase-II(UHS-II) - is a card receiver based on UHS-I. The theoretical speed of the UHS-II bus is 312 Mb/s, which is 3 times faster than its predecessor. UHS-II was introduced in 2011 as part of the SD specification version 4.0.

New SD and microSD cards now have an additional line of contacts, which, in fact, allows them to support the UHS-II interface. The top line processes the signal for high speed and UHS-I interfaces by default. In addition to this mode, UHS-II adds two additional modes: FD156 (156 Mb/s, 52 MHz, 0.4 V) and HD312 (312 Mb/s, 52 MHz, 0.4 V).

The high speed of the HD312 bus is achieved by using two low voltage data lanes, each offering a read/write speed of 156 MB/s. However, half-duplex mode allows only one lane to function at a time. In full duplex mode, two lanes operate, but data can still only be sent on one of them.

Unlike UHS-I, UHS-II is manufactured with support for only one type of card, known as UHS156. The card type may be with or without support for HD312 transmission mode. A UHS156 card without HD312 mode can reach a maximum speed of 156 MB/s. In addition, the host device must be compatible with UHS-II bus modes.

What is a UHS-III SD card

In 2017, the SD Association released a version of the cards SD Specification Version, defining new interface tires UHS-III. As expected, UHS-III provides a significant increase in speed compared to UHS-II.

First of all, the speeds of full-duplex data lanes have been improved. Extending the limits of UHS-II, UHS-III introduces two new full-duplex modes: FD312 (312 Mb/s) and FD624 (624 Mb/s).

Another incredible benefit of the UHS-III bus is that it reduces the time it takes for an SD card to transition from a power-saving state (the state when the card is not in use) to an active state.

Since the tires were released not so long ago, finding SDHC and SDXC cards on the market will be very problematic. They fit perfectly into work with devices that require fast data transfer. For example, you can, without worrying about quality, record material with a resolution of 8K, 4K and even 360-degree videos.

Which SD card should you choose?

After reading the material presented above, you must be at a loss as to which card to buy. We want to note that with each subsequent version of the UHS bus interface, the performance of the cards continues to grow rapidly. When using a UHS card and a USB drive, you will notice a clear performance difference in favor of the former.

A microSD or SD card with a UHS-I interface is perfect for daily use. If its speed does not meet your needs, purchase a card built on UHS-II.

In conclusion, the main widely used criterion for choosing an SD card is speed. You've probably already heard about classes such as 4 or 10; they are always written on drive cases. They are the ones who divide SD cards by speed.

Just in case you need to recover information from a UHS-I or UHS-II SD device, Starus Recovery tools will help you. You can download and try the program for recovering deleted data from a memory card completely free of charge!