Among the most successful flash memory standards present in today's global market is SD. One of its popular varieties is SDHC. Based on appropriate technology, leading world brands produce sufficiently capacious and reliable memory cards. What are the features of this standard? How did devices supporting SDHC come about?
SDHC Card Specifics
SDHC memory cards (or Secure Digital High Capacity) are devices that work according to the standard that has become a further development of SD memory technologies developed by the SD Card Association. The peculiarity of these devices is that their capacity can reach 32 GB. The file system that is most often used on such memory cards is FAT32.
One of the standards within which the SDHC memory card can be produced is micro. But in this case, together with the device, as a rule, you need to use an SD adapter, with which you connect to a PC or other device that uses flash memory.
It usually comes complete with micro memory modules .
Compatibility
It should be noted that a memory card complying with the SDHC standard may not be compatible with devices that were originally designed to work with ordinary SD-cards. The fact is that it uses the principle of sector-by-sector addressing (as in hard drives), in contrast to the byte-based one, which is implemented in memory cards of the previous generation.
SD Card Development History
Before global IT engineers developed a standard SDHC memory card, this was preceded by a long and systematic work by leading industry brands to standardize and improve the technology of flash devices used to store files. So, in 1999, SanDisk, Toshiba, as well as Matsushita decided to create a new standard - SD, or Secure Digital. What was its specificity?
First of all, in DRM support according to SDMI criteria. In accordance with the concept proposed by the three brands mentioned above, the SD-format of the memory cards was supposed to compete with Sony's already known Memory Stick technology. Three brands have created a new organization called SD Assiciation. Subsequently, its structure included the largest brands - such as, for example, Intel, AMD, Samsung, Apple.
Under the SD technology, 4 major generations of flash cards have been released. The very first, operating on SD 1.0 technology, is capable of placing data in a volume of up to 2 GB, the second - SD 1.1, works within a file volume of up to 4 GB. The limit that characterizes an SDHC memory card is 32GB. The next generation of flash memory - according to the SDHX standard, can accommodate up to 2 TB of files.
They use SD cards and those that support the SDHC standard in a wide variety of digital applications. Appropriate devices can be used as carriers of almost any type of file. They are extremely productive in terms of use in photo and video equipment. SD cards are affordable, reliable. Devices using SDHC technology are also characterized by quite decent capacity.
How did SDHC cards come about?
How did SDHC memory cards appear on the IT device market? The first devices working in the SD standard, as we noted above, initially housed only up to 2 GB of data. 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 increased. In 2006, a new, more advanced flash memory standard, SDHC, appeared. In the same year, SD Associations also developed several speed classes for their respective devices. Within each of them, the minimum speed value (in MB / s) for reading or writing files was recorded.
SDHC memory cards, in general, coped with the assigned user tasks. However, the needs of digital electronics enthusiasts have continued to grow. This is how the SDXC standard came about, with files up to 2 TB in size. Although, it should be noted, such devices are rarely found in the open market and are expensive (cheaper, as a rule, to buy an external hard drive).
The file system installed on the latest SD cards - exFAT, which has become a further development of FAT32. Among the significant advantages of the new standard proposed by Microsoft is the reduction in the intensity of data overwrites within one sector.
How to choose the best SD card?
In some cases, a PC user may wonder what is better to buy - SDHC memory cards or, for example, SDXC devices? 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, the old model do not always support flash memory released using the latest technology. At the same time, which is noteworthy, 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 turn out 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.