Many people can not imagine their life without electronics today. We photograph the important moments of our life with a digital camera, communicate with a mobile phone, write texts using a computer. This is a huge flow of information that should be stored somewhere. Many methods were devised to store information (for example book is also a storage device :)) and many special devices were developed for this purpose.
Today we will look at the possibilities and characteristics of the devices which mainly used for storing and transmitting information in small portable electronic devices. We will discuss how to choose a digital memory card in this article.
I wrote about choosing a hard drive for a computer that plays a major role in PC information storage recently. Logically that in portable devices (laptops do not count) has to be their own “hard drive”. Such devices are usually small in size, so this storage drive has to be as small as possible. Digital memory cards were invented precisely for these tasks.
Digital memory card is a compact size storage device that is used for recording, storing and transmitting of information.
Let’s look at the basic memory cards features that you should consider when purchasing it:
1. Memory card format.
Many formats of memory cards are available on the market at this time. This was facilitated by the fact that many consumer electronics manufacturers have tried to create their own cards format before.
However, there is a strong tendency to unification and using of only certain formats now.
The most popular format is the SD card format (this is an abbreviation of Secure Digital Card). This format was invented in 1999 and become widespread since that time.
Secure digital memory card is different from its predecessors by the ability to protect information from unauthorized access, as indicated by the abbreviation «Secure».
There are several types of SD cards, which differ in size. SD memory card sizes are the follows:
– Standard SD card – size 2.1 mm (thickness) × 32 mm (length) x 24mm (width);
– Mini secure digital (mini SD) Card – size 1.4 x 21.5 x 20 mm;
– Micro secure digital (micro SD) Card – size 1.0 (0.7) x 15 x 11 mm.
Standard SD cards are used in portable devices with relatively large sizes, for example, almost in all digital cameras. Mini SD and micro SD are used in smaller devices, such as mobile phones and Mp3 players.
Memory card adapters which enable using of mini SD and micro SD card in the slots for standard cards were designed for convenience of consumers. “Small” card is inserted into the adapter and can be used as a “big” card.
The need to use compact memory cards to store large amounts of information occurred shortly after starting of SD card format using.
SD format was modified for this purpose and SDHC (Secure Digital High Capacity) format was invented.
SD card can hold up to 4 GB of information, while SDHC cards can already hold up to 32 GB.
SDXC cards are the next generation of SD cards. This new memory cards were appeared recently and they can hold up to 2TB of information.
SDHC and SDXC cards can also be standard, mini SDHC (SDXC) and micro SDHC (SDXC) by the size.
It should be noted that each generation of SD cards support the previous generation, but not vice versa. For example, if the camera works with SDHC card, it will work with SD, but not with SDXC.
Other formats of memory cards, such as Compact Flash, Microdrive, Multimedia Card, Smart Media, Memory Stick, xD-Picture are also used in addition to SD formats. Many of these formats are gradually losing its position in the market for SD cards. Most of these formats are used in highly specialized technique or only in certain product manufacturers.
When buying some device find out what type of card it uses first of all, such information should be in the manual for that device.
2. Memory card speed class.
SD cards are now the most popular as we said above
Speed of recording of information is one of the main parameters of cards, which affects its performance.
This speed is measured by the number of megabytes that card can record for 1 second.
Speed classes were introduced to classify different cards by one scale.
The following memory card class rating is the most common now:
Class 2. It has the speed of information record at least 2 MB per second;
Class 4 – at least 4 MB/sec;
Class 6 – at least 6MB/sec;
Class 10 – at least 10 MB/sec;
Class 12 – at least 12 MB/sec;
Class 16 – at least 16 MB/sec.
Class 45 cards also exist in principle, but they are rare.
To the question “what class of memory card is better?” answer is very simple, because it is clear that better and faster card has a higher class.
There is a recommended minimum speed class for each device.
For example, the card with speed class not below 4 can be recommended for mobile phones, for cameras not below than class 6.
Requirements to speed of cards will only increase every year. Cards with class 2 are almost unclaimed already.
3. Memory card capacity.
Memory capacity indicates how much information can be holding on the card. This amount is measured in gigabytes.
The maximum amount of memory that can be easily found on the market is 128 GB, the minimum is 2 GB.
You have to know what memory capacity is supported by your device. For example, if you will put 16 GB card to not very new mobile phone – it can simply not recognize this card.
Many experts advise to buy more cards of smaller capacity than fewer cards with larger capacity. For example, it is better to buy two 16GB cards than one 32 GB card.
These recommendations come from the fact that valuable information is better to keep not on one card, but on several. If the card will failed, you will lose not all information, but only part of it.
By the way, you can also buy a special device for reading memory cards – card reader, when buying a card.
Digital memory card reader is a device through which you can easily transfer information from different cards to your PC or vice versa. Digital card Reader connects to PC via any USB port. Choosing a card reader, please check whether it supports the necessary cards formats.
I hope you’ll know which digital memory card to choose and your information will be securely stored after this review of the features and specifications of memory cards.