SD is one of the most successful flash memory standards on the world market today. One of its popular varieties is SDHC. Based on the appropriate technology, the world's leading brands produce sufficiently capacious and reliable memory cards. What are the features of this standard? How did SDHC devices appear?
Specific SDHC cards
SDHC (or Secure Digital High Capacity) memory cards are devices that operate according to a standard that is a further development of SD flash memory technologies developed by the SD Card Association. The peculiarity of these devices is that their capacity can reach 32 GB. The file system most commonly used on these memory cards is FAT32.
One of the standards within which an SDHC memory card can be produced is micro. But in this case, along with the device, as a rule, you need to use an SD adapter, with which you can connect to a PC or other device that uses flash memory.
It usually comes with standard memory modulesmicro.
Compatibility
Please note that an SDHC compliant memory card may not be compatible with devices that are originally designed to work with regular SD cards. The fact is that it uses the principle of sector-by-sector addressing (as in hard drives), unlike byte-by-byte addressing, which is implemented in memory cards of the previous generation.
SD Card Development History
Before the world's IT engineers developed an SDHC-compatible memory card, this was preceded by a long and systematic work of the industry's leading brands to standardize and improve the manufacturability of flash devices used for file storage. So, in 1999, SanDisk, Toshiba, and Matsushita decided to create a new standard - SD, or Secure Digital. What was its specificity?
First of all, in support of DRM in accordance with SDMI criteria. In accordance with the concept proposed by the three brands mentioned above, the SD memory card format was to compete with Sony's already well-known Memory Stick technology in the market. The three brands formed a new organization called the SD Assiciation. Subsequently, its structure included the largest brands - such as, for example, Intel, AMD, Samsung, Apple.
Within the framework of SD technology, 4 main generations of flash cards have been released. The very first, which operates on SD 1.0 technology, is capable of placing data up to 2 GB, the second, SD 1.1, works within the file size of up to 4 GB. The limit value thatcharacterized by a memory card SDHC - 32GB. The next generation of flash memory - according to the SDHX standard, can store up to 2 TB of files.
SD cards and those that support the SDHC standard are used in a wide variety of digital applications. Appropriate devices can be used as carriers of almost any type of file. They are exceptionally productive in terms of use in photo and video equipment. SD cards are available, reliable. Devices using SDHC technology are also characterized by quite a decent capacity.
How did SDHC cards come about?
How did SDHC memory cards appear on the IT device market? The first devices operating in the SD standard, as we noted above, initially placed only up to 2 GB of data in themselves. For a long time, this resource was enough to perform basic user tasks - for example, placing documents, photos, music files.
Gradually, the needs of computer owners have increased. In 2006, a new, more advanced flash memory standard appeared - SDHC. In the same year, SD Associations also developed several speed classes for related devices. Within each of them, the minimum speed value (in MB / s) for reading or writing files was fixed.
SDHC memory cards, in general, coped with the user's tasks. However, the needs of digital electronics enthusiasts have continued to grow. This is how the SDXC standard appeared, which involves placing files up to 2 TB. Although, it should be noted that such devices are on open salerare and expensive (it's usually cheaper to buy an external hard drive).
The file system installed on the latest SD cards is exFAT, which has become a further development of FAT32. Among the significant advantages of the new standard proposed by Microsoft is a reduction in the intensity of overwriting data within a single sector.
How to choose the best SD card?
In some cases, a PC user may be faced with the question of what is better to buy - SDHC memory cards or, for example, devices according to the SDXC standard? It all depends, first of all, on the required capacity of the device. Another criterion is the compatibility of a computer or other device with the corresponding standard. The fact is that devices - cameras, PCs, card readers, of the old model do not always support flash memory released using the latest technology. At the same time, it is noteworthy that support for certain standards may depend not only on the hardware functions of the device, but also on the version of the firmware used on it. It may well be that a simple software update will help the device - for example, the same camera, learn to recognize the latest SDHC or even SDXC memory cards.
