memory card

All about SD Memory Cards

“It seems incredible that a piece of plastic so small to be able to store as much information”. Most likely is that is the thought that crosses our minds every time we have in our hands a memory card. This reflection has, of course, a good solid grip. Those who that remember the old diskettes, with its huge size and its 360 Kb. of capacity, knows the hardships they suffered whenever had to store something that occupied more of this limitation.

Of course the computer at that time was much simpler, and scenarios to need more of that capacity, limited. But since those days until today, technology has advanced, allowing the creation of increasingly precise and complex instruments, and with them came the need to store the huge amount of data they generate or they need to function.

All about memory cards

It is currently not possible to think about to buy a device without accompany it with its corresponding SD memory card. We’re not just talking about digital cameras, but also video cameras, MP3 players, PDAs, GPS, smartphones, tablets, TV Box and many other electronic devices, each with its corresponding type of memory card. Therefore it is good to be informed about the various options that exist in SD memory cards, information that can be obtained easily if continues reading this article.

While on the market there a wide variety of memory cards from different manufacturers and with many different purposes, such as Compact Flash, Memory Stick, MultiMedia Card and others, the truth is that the most popular format memory card is called card SD memory, acronym of Secure Digital, the which has very good references of all who use it daily, and that is why it has become a standard widely used, together to their “brothers” Mini SD and Micro SD, the latter being the most widespread.

All about memory cards

Main features of the SD Memory Card

Some interesting features found on SD memory cards are its small size and large capacity, as well as its compatibility with all kinds of devices, points that will explain below in the article.

Formats SD memory cards

The format is asymmetrical, therefore no risk of being inserted by mistake on your computer, besides having a good small size:


Traditional SD Memory: 32 mm x 24 mm x 2.1 mm
Mini SD memory: 20 mm x 21.5 mm x 1.4 mm
Micro SD memory: 11 mm x 15 mm x 1 mm


Storage Capacity SD Card

The SD memory card offers different storage capacities: 8, 16, 32, 64, 128, 256 and 512 MB, although such cards are hard to find, as they have been replaced in the market for cards with much greater capacity: 8, 16, 32 and 64 Gb, and until they can even reach up to 128 Gb. of storage space. It is important to remember that not all computers have support for cards with 2GB or more, due to the difference in formatting (sometimes the problem is solved by firmware upgrade that computer).

All about memory cards

First, it is important to decide the storage capacity of the memory card. But we should not get a wrong idea, because the capacity bought never enough, much less in the camera of a teenager who is on vacation!

The fact that digital cameras offer more and more megapixels without increasing the price, creates the need for more memory to fit the photographs, a higher definition occupy more space.

All about memory cards

Card compatibility SD, MiniSD and MicroSD

In this sense, MicroSD type cards are more compatible than MiniSD and the SD type, perhaps because they are the most widespread type of memory market. Used by countless manufacturers of digital machines such as Casio, Canon, Nikon, Pentax, Kodak, Panasonic, Konica/Minolta and manufacturers of electronic devices around the world, are included with all kinds of devices like smartphones, tablets, PDAs, mp3 players and much others. However, if your device only accepts SD cards type, also called Transflash, this is not inconvenient to use, because in the market there are adapters that can convert a MicroSD or MiniSD memory card into SD type.

SD memory cards safety and security

The SD memory cards have a physical lock system which prevents the writing on the card, similar to the recording obstacles included in the old 3.5 diskettes, although the market we can find cards cheaper models without this feature. However, unlike diskettes, this blocking is performed by the firmware of the device detects that the key is activated.

The card contacts are placed in a depression of the card, so as to avoid contact with the dirt left by hands and other materials.

All about memory cards

Memory cards speed

Memory cards can have different transfer rates (which also varies in price), according to the version used. Speed is measured in multiples of 150K (equal to CD-ROM). The most usual is to find cards or equipment that use up to speeds of 16x (2.4 MByte / sec), and some faster than 66x (10 MByte / s), although they can also be ultra-fast 150x or even 133x cards.

In fact, many times the speed and capacity to transfer data to the computer of these cards can only be exploited if we have a USB 2.0 port. However, if you are thinking of using more advanced equipment and professional semi-professional camera, or SLR, will certainly better benefits in the use of faster memory cards.

Memory card peed table


4x: 600 KB / s
16x: 2.4 MB / s
32x: 4.8 MB / s (SanDisk Pro)
66x: 10MB / s (SanDisk Extreme, SanDisk Ultra II)
133x: 20 MB / s (SanDisk Extreme III, Lexar Professional)


Other functions:

Because of its great popularization, the SD Card Association, entity responsible for the standardization of this class of devices, defining today the new features and applications such as the ability to add a Wi-Fi device within the card itself, devices that can already be found in some electronics stores.

All about memory cards

Examples of such implementations are:

SD Card with Copyright, used for film distribution, which allows the user to purchase an SD Card containing a DVD movie format, which can be played on computers and portable devices like PS3.

Using SDIO technology, which allows, using the dimensions of the card and using their pins, the use of devices such as Bluetooth and Wi-Fi receivers, among others.

While this format is here to stay, there are significant differences in features, capacity and price. It is therefore necessary, before buying, learn more to better select the model that will bring the expected result in our equipment.

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