External storage devices (VIZ): characteristics, purpose, types, classification.

Any owner of a personal computer or laptop must have heard about external storage devices, but what it is and what it looks like, it was not possible to see in reality. It's time to remove gaps in knowledge and get to know the wonderful gadgets and technologies that can make life easier for any user.

In the focus of this article, external storage devices. The reader is invited to find out how they look, their operation principle and the main purpose of using this technique in everyday life. Also, the user will get acquainted with modern devices, learn their characteristics, types and classification.

There must always be a motive

Any technique that appears on the market must certainly perform some tasks, otherwise there will simply be no demand for the novelty. External storage devices (VCDs) are required for data storage. And the information in such cases has large volumes and must be preserved in integrity for a long period of time. Accordingly, the requirements to the devices themselves also appear: reliability and volume, without which there will be no result. However, the reader should know that in addition to the basic requirements, there are secondary tasks:

• The speed of writing information - the higher it is, the better for the user;
• The cost of the recording device and media ;
• Encryption support - there are also secret data;
• Compatibility - good, when the medium can be read on another computer.

As practice shows, it is impossible to find a universal device that could meet all the requirements. Therefore, buyers often resort to balancing, deciding for themselves what is more important to them. In any case, every user finds exactly what he needs on the market.

End justifies the means

Many readers will be interested in the classification of external storage devices. It so happened that on the computer market there is a strict division of products according to their basic criteria:

1. Capacitive . In the context of a large enterprise, which has a huge database, it is the capacity of the carrier that comes first. Here we are talking at least a dozen terabytes, which must be kept daily.
2. High-speed . In most cases, fast recording is only necessary for those enterprises and organizations where you want to store multimedia content (sound and video). It should be noted that in such situations there is no question of the long-term storage of data.
3. Simple . In the home segment in the first place is the cost and ease of use. Naturally, for the average user, compatibility and high speed of writing and reading information are not superfluous.
4. Reliable . This criterion is better called long-term, because the concept of reliability for all media is different.

And whether it is necessary?

The purpose of external storage devices for each consumer is different. Large enterprises need to save daily changes in the database. The fact is that large amounts of information can not simply be placed on the basis of several servers and many computers. And to the documentation of the past periods it is always necessary to address, for example, for analytics or for creating reporting.

Home users can conveniently reserve multimedia content, saving photos, video, or music files. By the way, many owners of computers and laptops naively believe that the information is stored securely on the hard disk. However, very few people know that a constantly working hard drive dramatically shortens the service life and not reserved information can simply get lost. It is for this purpose that the users' computers in the store are equipped with DVD-drives that allow recording on optical disks.

Universal optics

Yes, optical media are the simplest example. Here, external storage devices are CD-, DVD-, HD- and Blu-ray-discs. The main criterion for such carriers is the high reliability of data storage. It is an average of 70-100 years. True, this indicator is only feasible for reliable protection of disks from physical impact.

As for the volume, here we can already see the division into categories, where CD and DVD disks are given 700 MB and 4 GB respectively, and Blu-ray media is 25-50 gigabytes. Even with the volume, the cost of the writing device increases with the media. Do not forget about the speed of recording - since optical devices inflict information on the disk linearly (laser is one), then it takes a lot of time to write a large-capacity disc.

IT Professionals' Recommendations

However, optical external storage devices of a computer are still popular among home users, as well as in demand in a small business where there is a workflow or there is a small database. Professionals recommend giving preference to conventional DVD-drives. The fact is that this device is in the golden middle by the criterion of "price-quality". And with compatibility, users will never have problems.

It is worth paying attention to the user and the possibility of rewriting information (though, for this you will have to purchase the appropriate media). In any case, the buyer will receive a decent external storage device, which has the most necessary qualities. The LG, Samsung and Asus manufacturers have proved themselves in the market of optical drives. But the media is better to buy under the brand Verbatim - this company does not have defective products.

Nonvolatile memory

Yes, conventional flash drives and SSD-disks can also be considered as VCD, but in those cases when it comes to home use, or short-term storage of data. The fact is that capacitances with non-volatile memory have a high cost in the ratio of "price-volume" and unreliable. As practice shows, the same flash drive can easily be rendered unusable by the usual static discharge of electricity, which accumulates in the human body. Such a characteristic of modern external storage devices obviously does not play in favor of seemingly simple and reliable equipment.

It is not necessary to harbor illusions that the situation with NAND-memory will change in the coming years. Volumes will grow in direct proportion to value. The problem with the static can not be solved, because then there will be no need for consumers to purchase new devices. For medium and large businesses, as well as for factories and enterprises, such a carrier of information is hardly useful as a reliable information keeper.

Unreliable devices

Experts recommend that all beginners who are poorly versed in computer technology, exclude from the list of external storage devices such as a memory card and flash drive. It's not for nothing that these products are even in store windows in the accessories department, and not with reliable data storage devices.

Problems with such drives are plenty. Starting from a normal failure under the influence of static voltage, ending with a banal physical damage as a result of falling or moisture on the contacts of the device. Yes, this technique is inexpensive, it is easy to use and has a large volume. But its basic purpose is short-term storage of data, which is necessary in case of transportation. On this merit of this product and ends.

How to choose a USB flash drive?

The characteristics of external storage devices based on Flash is only one - it's the speed of data recording. Do not need the buyer to look at the appearance or convenience, color or equipment, everything is decided by the built-in controller, which simply has to work quickly regardless of the size of the drive and the connection interface.

If we talk about memory cards, then the choice here is quite simple - you need to focus on the class of the device. The lower it is, the slower the information is recorded on the medium. Ideally, preference should be given to the 10th grade and Ultra labeling. Speaking of brands, Transcend, Pretec, SanDisk and Team have proved themselves well in the market.

But with USB-drives everything is much more complicated. Here, most manufacturers are silent about the speed of recording. These brands a priori, do not even pay attention. All devices with a decent speed of operation directly on the package indicate the recording speed in USB 2.0 mode. External storage devices Kingston, Pretec and Transcend here, of course, are leaders. The speed of recording such devices clearly exceeds 10 megabytes per second. And this is really a worthy indicator.

An interesting way out

It is worth noting that modern external storage devices, high-priced SSD disks, along with high-speed indicators, also have worthy reliability in a certain sense. The fact is that nonvolatile memory cells under the influence of an electric field are not overwritten to zero, as is the case with conventional flash drives.

Yes, as a hard drive SSD-disk after the damage already can not work. But it will turn into one huge flash drive, from which you can read previously recorded information. It is this feature that attracts potential buyers to a completely new technology in the computer market, because the reliability of data storage for the majority is a priority.

Ready-made solutions in the computer market

The basic characteristics of external storage devices, in terms of SSD-drives, is the minimum cost of one unit of recorded information. That is, the user must determine the product on the market, the price of which corresponds to the volume. To find out it is quite simple - you need to divide the cost by the size of the SSD-disk. So the buyer learns how much is 1 gigabyte of recorded information on the carrier. On average, the cost of 1 GB should not be more than 10-15 rubles.

It is logical to assume that it is advantageous to purchase a device with only a large amount of data (more than 640 gigabytes). Yes it is. As for specific brands, the choice here is quite large. The fact is that all manufacturers are trying to win the favor of the buyer and provide really worthy products on the market. Well proven brands: Transcend, Toshiba, Kingston and Samsung. The buyer should pay attention to the data transfer speed, for each manufacturer it is different.

Jump through the decades

To date, the most reliable and efficient device is a tape drive, which is capable of recording data with high density on a special tape with a magnetic tape. Since the main characteristics of external storage devices are reliability and volume, the world does not have any other device with similar characteristics. Here the record is measured only in terabytes, and not in tens, but in hundreds. As for compatibility, there will not be any questions here either - knowing the key to the encoded information, it will be easy to read it from the tape.

In general, for streamers, there is a lot of interesting software that is able to modify (encode and compress) data, allowing the end user to increase the density of the record or the reliability of storage. The technology has outlived its time, but in view of the complete lack of replacement, developers, programmers and technologists, whose work is directly connected with streamers, have to constantly improve the device and storage media, forcing the technology to work at the limit of its capabilities.

The choice is always

It is worth noting that users do not necessarily have to purchase the streamer on the market. The fact is that the Russian instrument-making plant has long established the production of special adapter cards that can combine a conventional video recorder and a personal computer. However, in this case, you need an adapter under the cassette.

The external storage devices of a computer called a streamer on an ordinary computer market are not available to the user. This specialized equipment and find it can only be solders who are engaged in the delivery of server equipment. Streamers from HP and Dell have proven successful. Brands in the market are not one decade old and managed to gain the trust of system administrators and IT professionals. Present in the market and Chinese representatives with the product Lenovo. They provide the user with a decent functionality, but the demand for a novelty is still too low.

Technologies of the last century

Magnetic external storage devices, such as a tape drive or floppy disk, have one serious drawback that can easily lead to the loss of important information on the media. The fact is that any magnet can be demagnetized. That is, any record, placed in a special electromagnetic field can be easily destroyed. In the context of a large enterprise, cassettes for the streamer are transported and stored in a specialized box that does not transmit electromagnetic radiation.

Also to VZU many experts try to include Floppy and ZIP-diskettes. The conversation on these carriers is short. Technologies were relevant only at the stage of the origin of the computer. In the future, these carriers just left the high-tech market, and at the moment are simply not considered as a reliable data store.

Inexpensive solution

External storage devices (HDDs) include ordinary hard disks HDD. Many users are sure that the reliability of these devices are inferior to other media, but this opinion is erroneous. The fact is that this reasoning of readers leads to cases associated with the loss of important information in the event of a serious breakdown of the Windows operating environment. However, few people know that lost data can easily be recovered with the help of special utilities.

In fact, on hard magnetic disks valuable information can be stored for almost a decade, the main thing is periodically to re-record the data and monitor at the program level behind the integrity of the magnetic surface of the disk. By the way, it is the ordinary hard drive that stands in second place after the streamer on the profitability of the acquisition in the "price-volume" category.

Without recommendations, there is no purchase

Having found out that external hard drives are usual hard drives, the reader will certainly want to know which product to give preference to, because there are so many different offers on the market. As practice shows, it is better to focus on the amount of buffer, which is equipped with any hard drive. Also important is the speed of rotation of the spindle, but this indicator is inextricably linked with the noiselessness of operation - these two parameters are inversely proportional to each other.

As for the choice of the manufacturer, it is better to give preference to brands that are mentioned positively in the users' reviews: Seagate, Hitachi, Toshiba. Again, the buyer should be guided and at the price of one gigabyte, dividing the cost of a hard drive by its volume. At least, so you can find out the feasibility of buying.

NAS platforms and RAID arrays

Using the case, I would like to note that on the basis of hard magnetic drives there are specialized types of external storage devices. It's about combining several hard disks into data arrays. A special controller at the hardware and software level can form disks, creating parallel or serial connections. That is, several disks can be aligned as one large drive, or there is a possibility of duplicating the recorded data on different media.

Everything here depends on the needs and capabilities of the user. For the reliability of storage, arrays are created, which, like mirrors, duplicate important information. But for the sake of volume, NAS systems are used that can manage the flow of information and quickly record important data on media.

Finally

Any user will agree that external storage devices are an integral part of a personal computer or laptop. Whatever one may say, for reliable data saving, the user needs to use the VCU, choosing for himself the best option according to the general classification.

It turns out that potential buyers do not need to be afraid of strange terminology, because it hides a lot of known devices that readers have to deal with every day every day.