03.03.2018
A storage device is a device on which all computer data is stored. In addition to the drive, this device is called a hard drive or hard drive. A hard disk differs from a conventional “floppy” disk, or in other words, a floppy disk, in that information is recorded on hard plates made of aluminum or ceramics, and on top they are covered with a ferrimagnetic material. Hard drives are equipped with one or more platters on an axle.
The data storage device (HDD) is composed of a sealed unit and an electronic board. The hermetically sealed unit is filled with normal, dust-free air by atmospheric pressure and is equipped with all mechanical parts. The kinematics of the data drive includes one or more magnetic disks, which are rigidly fixed to the motor spindle, as well as a system responsible for positioning the magnetic heads. The magnetic head occupies a place on one of the sides of the moving magnetic disk and its functional duties include reading and writing data from the rotating surface of the magnetic disk. The heads themselves are attached with special holders, and their movement is carried out using a positioning system between the edge and the center of the disc. It is possible to achieve precise positioning of magnetic heads by means of servo information recorded on the disk. The positioning system, reading this information, is able to determine the strength of the current passed through the coil of electromagnetic wire so that the magnetic head can be fixed over the required track.
After the power is turned on, the processor of the hard drive (drive) begins to test the electronics, after which a command is issued to enable the process of directly turning on the spindle motor. As soon as initialization is completed, testing takes place positional system, during which the tracks are traversed, in the specified sequence. If the test went well, the hard drive sends a signal that it is ready to go. To increase the level of reliability of computer information storage, hard drives (drives) are equipped with a special firmware that monitors the technological parameters available for the reading and analysis program. If the computer is in danger of failure, then with the help of this program the user will know about it in a timely manner.
In addition, the data storage is a hybrid hard drive, which consists of a traditional hard drive, equipped with additional flash memory. This flash memory is completely non-volatile and is assigned the role of a buffer in which the most frequently used data is stored. As a result of the activity of this device, access to the magnetic disk is reduced, which accordingly leads to a decrease in power consumption. Also, the level of reliability of storing information is increased, the time required to boot and to wake the system from sleep mode is reduced, and the temperature and acoustic noise that the hard drive emits are significantly reduced.
The attractiveness of the USB interface is in its simplicity - just plug in a USB flash drive or other storage device and you can work, no driver installation or other additional steps are required. The development of the interface and the appearance of USB 2.0 first, and then USB 3.0, dramatically increased the speed of data exchange over this channel. The performance now differs little from the internal one, and their size cannot but rejoice. An external memory drive fits easily in the palm of your hand, while it allows you to store hundreds of gigabytes of information.
Introduction
1. Magnetic drives
1.1 Magnetic disk drives
2. Types of magnetic media
2.1 Floppy disks
3. Optical technology
3.1 CDs
3.2 DVD media
Conclusion
Bibliography
magnetic media hard magnetic
Introduction
The information storage devices produced are a range of storage devices with different operating principles, physical and technical performance characteristics. The main property and purpose of information storage devices is its storage and reproduction.
Memory devices are usually divided into types and categories in connection with their principles of operation, operational, technical, physical, software and other characteristics. So, for example, according to the principles of functioning, the following types of devices are distinguished: electronic, magnetic, optical and mixed - magneto-optical.
Each type of device is organized on the basis of the appropriate digital information reproduction/recording storage technology. Therefore, in connection with the type and technical design of the information carrier, there are: electronic, disk and tape devices.
Magnetic disks are used as storage devices that allow you to store information for a long time, when the power is off. To work with magnetic disks, a device called a magnetic disk drive (MDD) is used. The main types of drives: floppy disk drives (FPHD); hard disk drives (HDD); magnetic tape drives (NML); drives CD-ROM, CD-RW, DVD.
They correspond to the main types of media: floppy disks (Floppy Disk); hard magnetic disks (Hard Disk); cassettes for streamers and other NML; CD-ROMs, CD-Rs, CD-RWs, DVDs.
1. Magnetic drives
Magnetic drives are the most important medium for storing information in a computer and are divided into magnetic tape drives (NML) and magnetic disk drives (NMD).
Typically, magnetic recording uses pulsed signals. Bit information is converted into alternating current in accordance with the alternation of zeros and ones.
This current enters the magnetic head and, depending on the direction of the current in the head winding, a corresponding magnetic flux arises in the space between the head and the carrier, which closes through an elementary region of magnetization (domain). The intrinsic magnetic fields of the domains are oriented in accordance with the direction of the external magnetic field. When the external field is removed, this state of the domains does not change (long-term storage).
The main criterion for evaluating magnetic storage media is the surface recording density. It is defined as the product of the linear recording density along a track, expressed in bits per inch, and the number of tracks per inch. As a result, areal recording density is expressed in megabits (Mbps) or gigabits (Gbps) per square inch.
In modern 3.5-inch drives, this parameter is 10-20 Gb / inch, and in experimental models it reaches 40 Gb / inch. This allows the production of drives with a capacity of more than 400 GB.
1.1 Magnetic disk drives (MDDs)
NMD provides a similar NML possibility of sequential access to information. A magnetic disk drive combines several sequential access devices, and the reduction in data search time is ensured due to the independence of access to a record from its location relative to other records.
NMD technology. In NMD, as data carriers, a package of metal disks (or platters) is used, fixed on a rod, around which they rotate at a constant speed. The surface of a magnetic disk covered with a ferromagnetic layer is called the working surface.
The number of magnetic heads is equal to the number of working surfaces on one disk pack. If the package consists of 11 disks, then the access mechanism consists of 10 holders with two magnetic heads on each of them. The magnetic head holders are combined into a single block in such a way as to ensure their synchronous movement along all cylinders. The set of tracks achieved with a fixed position of the head unit is called a cylinder. The distance between the cylinders (tracks) is called the pitch, or track pitch. The process of controlling the recording density is called pre-compensation. To compensate for different recording densities, the zone-sector recording method (ZoneBitRecording) is used, where the entire disk space is divided into zones (eight or more), each of which usually includes from 20 to 30 cylinders with the same number of sectors.
In the zone located on the outer radius (the junior zone), more sectors (blocks) are recorded per track (120-96). Towards the center of the disk, the number of sectors decreases and in the oldest zone reaches 64-56. Since the speed of rotation of the disk is a constant value, more information is received from the outer zones during one revolution of the disk than from the inner zones. This non-uniformity of information receipt is compensated by an increase in the speed of the data reading / conversion channel and the use of special tunable filters for frequency correction by zones. At the same time, the capacity hard drives can be increased by approximately 30%.
1.2 Hard disk drives
The design and operation of the device. The HDD has several platters (discs) or platters installed inside the drive. The plates are either 5.25" or 3.5" in diameter. New designs are trying to use glass because it has more resistance and will allow thinner discs than aluminum counterparts.
Characteristics of HDD. The characteristics of a hard drive are very important in evaluating the performance of the system as a whole. Efficient performance hard drive depends on a number of factors.
Decisive among them is the speed of disk rotation, which is measured in rpm (rpm) and directly affects the data transfer speed in the hard drive. While the fastest EIDE hard drives were around 5400 rpm, SCSI HDDs can go up to 7200 rpm. The median drive access time is the interval between the time data is requested and the time data is accessed (measured in milliseconds (ms)). Access time includes actual search time, wait time, and data processing time.
Seek Time - The total time required for the read/write head to find the physical location of the data on the disk. The latency is the average access time to a sector during a rotation. It is easily calculated from the speed of rotation of the drive axis as a half-turn time.
A disk's transfer rate (sometimes called media speed) is the speed at which data is transferred to and read from a disk drive. It depends on the recording frequency and is usually measured in megabytes per second (MBps, MB/s).
The data transfer rate (or DTR- DataTransferRate) is the rate at which a computer can transfer data over buses (usually IDE/EIDE or SCSI) to the CPU. Some data providers specify an internal transfer rate, transferring data from the head to the built-in disk buffer. Others cite the data burst rate, the maximum data rate for ideal parameters, or for short duration. The speed of external data transfer is more important.
2. Types of magnetic media
2.1 Floppy disks
A floppy disk consists of a round polymer substrate coated on both sides with magnetic oxide and placed in a plastic package, the inner surface of which is coated with a cleaning coating. The package has radial slots on both sides through which the drive's read/write heads gain access to the disk.
Floppy disks of each size are usually double-sided. Single track density is 48 tpi (tracks per inch), double density is 96 tpi, and high density is typically 135 tpi.
When a 3.5" drive is inserted into the device, the protective metal shutter is pulled back, the drive spindle enters the middle hole, and the drive's side pin is placed in a rectangular positioning hole nearby. The motor spins the drive at 300 rpm.
Floppy disk drives use what's called "open loop tracking", they don't actually look for tracks, they just set the head to the "correct" position. In hard disks, by contrast, servo motors use heads to check positioning, which allows recording at a cross-sectional density many hundreds of times higher than is possible on a floppy disk.
The head is moved by the lead screw, which is in turn controlled by a stepper motor, and when the screw turns a certain angle, the head travels the set distance. The density of data recording on a floppy disk is limited by the accuracy of the stepper motor, in particular, this means 135 tpi for 1.44 MB floppy disks. The disk has four sensors: disk motor; write protection; the presence of a disk; and track sensor 00.
2.2 External hard drives
In recent years, technologies have spread to place standard hard drives in a mobile (portable) external case (box), which is connected to a computer via an external interface.
Since today the capacity of a hard drive is measured in gigabytes, and the sizes of multimedia and graphic files are measured in tens of megabytes, a capacity of 100 to 150 MB is enough for the media to fill the traditional niche of a hard drive - moving several files between users, archiving or backing up individual files or directories, and forwarding files by mail. This range offers a range of next-generation floppy drives that use floppy media and traditional magnetic storage technology.
Zi p-accumulators. Without a doubt, the most popular device in this category is the ZipIomega drive, first released in 1995. The high efficiency of Zip drives is ensured, firstly, by a high rotation speed (3000 rpm), and secondly, by the technology proposed by Iomega (which based on the aerodynamic Bernoulli effect), while the floppy disk "sticks" to the read / write head, and not vice versa, as in the HDD. Zip drives are soft like floppy drives, making them cheaper and less susceptible to shock loads.
Zip drives have a capacity of 94 MB and are available in both built-in and external versions. Internal modules conform to 3.5" form factor, use SCSI or ATAI interface, average seek time - 29 ms, data transfer rate - 1.4 Kbps.
Superdiskettes. The range from 200 to 300 MB best corresponds to the concept of superfloppy territory. The capacity of such devices is 2 times higher than that of the floppy disk substitute, and is more typical for an HDD than for a floppy disk. Devices in this group use magnetic or magneto-optical technology.
In 2001, Matsushita announces the FD32MB technology, which gives the option of high-density formatting a conventional 1.44 MB HB floppy disk to provide storage capacity of up to 32 MB per disk. The technology consists in increasing the recording density of each track on an HD floppy using a superdisk magnetic head for reading and a conventional magnetic head for writing data. While a conventional floppy disk has 80 circular data tracks, the FD32MB increases this number to 777. At the same time, the track feed from 187.5 µm for an HD diskette is reduced to about 18.8 µm.
Replaceable hard drives. The next capacity interval (from 500 MB to 1 GB) is enough to back up or archive a disk partition (partition) of a reasonably large size.
In the range above 1 GB, the removable disk technology is borrowed from conventional HDDs. Released in mid-1996, the IomegaJaz disk drive (replaceable 1 GB hard drive) was hailed as an innovative product. When Jaz hit the market, it was immediately clear where to use it - users were able to create audio and video presentations and transfer between computers. In addition, such presentations could be run directly from the Jaz media, without the need to rewrite the data to the hard drive.
Flash memory. Not related to magnetic media, flash memory works simultaneously like RAM and hard drive. It resembles ordinary memory, having the form of discrete chips, modules, or memory cards, where, just like in DRAM and SRAM, data bits are stored in memory cells. However, just like HDD, flash memory is non-volatile and retains data even when the power is turned off.
ETOX technology is the dominant flash technology, accounting for about 70% of the entire non-volatile memory market. Data is entered into the flash memory bit by bit, byte by byte, or words by an operation called programming.
While electronic flash drives are small, fast, consume little power, and can withstand shocks of up to 2000g without destroying data, their limited storage capacity makes them an inappropriate alternative to a PC hard drive.
3. Optical technology
3.1 CDs
In the beginning, CDs were used exclusively in high-quality sound-reproducing equipment, replacing obsolete vinyl records and tape cassettes. However, laser discs soon began to be used on personal computers. Computer laser discs were called CD-ROM. In the late 90s. a CD-ROM device became a standard component of any personal computer, and the vast majority of programs began to be distributed on CDs.
Compact disc drive (CD-ROM). Information is read from a CD using a laser beam of lower power. The servomotor, on command from the drive's internal microprocessor, moves the reflecting mirror or prism. This allows the laser beam to be focused on a particular track. The laser emits coherent light, consisting of synchronized waves of the same length. The beam, hitting a light-reflecting surface (platform), is deflected through a splitting prism to a photodetector, which interprets this as "1", and falling into a recess (pit), it is scattered and absorbed - the photodetector fixes "0".
While magnetic disks rotate at a constant RPM, i.e. at a constant angular speed, a CD usually rotates at a variable angular speed to ensure a constant linear speed when reading. Thus, the reading of internal tracks is carried out with an increased, and external - with a reduced number of revolutions. This is the reason for the lower data access speed for CDs compared to hard drives.
3.2 Media DVD
A universal digital disc (digitalversatiledisc- DVD) is a type of drive that, unlike CD, has been designed for wide application both in audio-video and in the computer industry. DVDs are the same size as a standard CD (diameter 120 mm, thickness 1.2 mm), provide up to 17 GB of memory at a transfer rate higher than CD-ROM, have access times similar to CD-ROM, and are divided into four versions:
DVD-5 - single-sided single-layer disc, with a capacity of 4.7 GB;
DVD-9 - 8.5 GB single-sided double-layer disc;
DVD-10 - double-sided single-layer disc 9.4 GB;
DVD-18 - capacity up to 17 GB on a double-sided double-layer disc.
DVD - ROM. As with the discs themselves, there are few differences between DVD and CD-ROM drives, as the only obvious thing is the DVD logo on the front. The main difference is that the CD-ROM data is written close to the top layer of the disc's surface, while the DVD data layer is closer to the middle so that the disc can be double-sided. Therefore, the optical reading unit of a DVD-ROM drive is more sophisticated than its CD-ROM counterpart to allow for reading either one or the other of these media types.
One of the earliest solutions was to use a pair of swiveling lenses, one to focus the beam on DVD data levels and the other to read normal CDs. Subsequently, more sophisticated designs have emerged that eliminate the need to switch lenses. For example, Sony's "double discrete optical sampling" has separate lasers optimized for CD (780nm) and DVD (650nm). Panasonic devices switch laser beams using a holographic optical element capable of focusing the beam at two different discrete points.
DVD-ROM drives spin a disc much more slowly than their CD-ROM counterparts. However, since DVD data is packed much denser, its performance is significantly higher than that of CD-ROM at the same rotation speed. While a normal audio CD-ROM (lx or single) has a maximum data transfer rate of 150Kb/s, a DVD(1x) can transfer data at 1250Kb/s, which is only achieved at eight times (8x) the speed of a CD-ROM .
There is no generally accepted terminology to describe the various "generations" of DVD drives. However, the term "second generation" (or DVDII) usually refers to 2x speed drives that are also capable of reading CD-R/CD-RW media, while the term "third generation" (or DVDIII) usually refers to 5x (or sometimes 4x) speed drives. ,8x, or 6x), some of which are capable of reading DVD-RAM media.
Recordable disc formats DVD
There are several versions of recordable DVDs:
DVD-R regular, or DVD-R;
DVD-RAM(rewritable);
recordable DVD . DVD-R (or recordable DVD) is conceptually similar to CD-R in many ways - it is a write-once media that can contain any type of information normally stored on a mass-produced DVD - video, audio, pictures, data files, programs, multimedia, etc. e. Depending on the type of information being recorded, DVD-R discs can be used on virtually any compatible DVD playback device, including DVD-ROM drives and DVD video players. Since the DVD format supports double-sided discs, up to 9.4 GB can be stored on a double-sided DVD-R disc. Data can be written to DVD at 1x speed (11.08 Mbps, which is approximately equivalent to 9x CD-ROM speed). Once burned, DVD-R discs can be read at the same speeds as mass-produced discs, depending on the x-factor (multiple of the speed) of the DVD-ROM drive being used.
DVD-R, like CD-R, uses constant line rate (CLV) to maximize recording density on the disc surface. This requires a change in revolutions per minute (rpm) as the track diameter changes as one moves from one edge of the disc to the other. The recording starts on the inside and ends on the outside. At 1x speed, the rotation speed varies from 1623 to 632 rpm for a 3.95 GB disc and from 1475 to 575 rpm for a 4.7 GB disc, depending on the position of the record-playback head on the surface. For a 3.95 GB disc, the track spacing (pitch), or the distance from the center of one turn of a spiral track to the adjacent portion of a track, is 0.8 microns (microns), half that of CD-R. On a 4.7 GB disk, an even smaller track feed is used - 0.74 microns.
DVD - RAM . The rewritable DVD-ROM or DVD-RAM uses phase change technology, which is not a purely optical technology of CD and DVD, but a combination of some features of magneto-optical methods and has its origins in optical disc systems. The applied format "surface-groove" (landgroove) allows you to record signals both on the recesses formed on the disk, and in the gaps between the recesses. Recesses and sector headers are formed on the surface of the disc during its casting.
In mid-1998, the first generation of reusable DVD-RAM products appeared with a capacity of 2.6 GB on both sides of the disc. However, these early devices are not compatible with higher capacity standards that use a contrast enhancement layer and a thermal buffer layer to achieve higher recording densities. The specification for DVD-RAM version 2.0 with a capacity of 4.7 GB on one side was released in October 1999.
DVD - RW . Formerly known as DVD-R/W or DVD-ER, DVD-RW media (which became available in late 1999) is part of Pioneer's evolutionary development of existing CD-RW/DVD-R technologies.
DVD-RW discs use phase change technology to read, write and erase information. A 650 nm laser beam heats the sensitive alloy layer to either crystalline (reflective) or amorphous (dark, non-reflective) depending on the temperature level and subsequent cooling rate. The resulting difference between the recorded dark marks and the erased reflective marks is recognized by the player or drive and allows the stored information to be reproduced.
DVD-RW media uses the same physical addressing scheme as DVD-R media. During the recording process, the drive's laser follows the microscopic depression, writing data in a spiral track.
One of the main advantages of the third DVD-DVD+RW rewritable format is that it provides better compatibility than any of its competitors.
DVD + RW . The DVD-RAM specification was a compromise between two different offerings from major competitors - the Hitachi grouping, Matsushita Electric and Toshiba, on the one hand, and the Sony/Philips alliance on the other.
DVD+RW shares many similarities with competing DVD-RW technology in that it uses phase change media and assumes the user experience obtained with CD-RW discs. DVD+RW discs can be recorded in either constant linear velocity (CLV) for sequential video recording or constant angular velocity (CAV) for direct access.
DVD + R . The two-layer DVD+R system uses two thin organic films of the material to be dyed, separated by a spacer (filler). Heating with a concentrated laser beam irreversibly changes the physical and chemical structure of each layer so that the changed areas acquire optical properties that differ from the original ones. This causes the reflectivity to fluctuate as the disc rotates and creates a read signal similar to that found in stamped DVD-ROM discs.
Conclusion
Thus, the following general conclusions can be drawn:
1. Magnetic drives are the most important medium for storing information in a computer and are divided into magnetic tape drives (NML) and magnetic disk drives (NMD).
2. Magnetic disks are used as storage devices that allow you to store information for a long time, when the power is off.
3. The main types of drives: floppy disk drives (FPHD); hard disk drives (HDD); magnetic tape drives (NML); drives CD-ROM, CD-RW, DVD.
4. The main types of media: flexible magnetic disks (Floppy Disk); hard magnetic disks (Hard Disk); cassettes for streamers and other NML; CD-ROMs, CD-Rs, CD-RWs, DVDs.
5. There are several versions of recordable DVDs: DVD-R regular or DVD-R; DVD-RAM(rewritable); DVD-RW; DVD+RW.
Bibliography
1. Golitsyna O. L., Popov I. I. Fundamentals of algorithmization and programming: textbook. allowance. M.: FORUM: INFRA-M, 2002.
2.Information technologies: textbook. allowance / O. L. Golitsyna, N. V. Maksimov, T. L. Partyka, I. I. Popov. M.: FORUM: INFRA-M, 2006.
3. Kaimin V.A. Informatics: textbook. M.: INFRA-M, 2000.
4. Maksimov N. V., Partyka T. L., Popov I. I. Computer architecture and computing systems: studies. allowance. M.: FORUM: INFRA-M, 2004.
5.Maksimov N. V., Partyka T. L., Popov I. I. Technical means of informatization: textbook. allowance. M.: FORUM: INFRA-M, 2005.
6.Maksimov N. V., Popov I. I. Computer networks: textbook. allowance. M.: FORUM: INFRA-M, 2003.
7. Nadtochy A.I. Technical means informatization: textbook. allowance / Under the total. ed. K. I. Kurbakova. Moscow: KOS-INF; Ros. economy acad., 2003.
8. Fundamentals of Informatics (textbook for applicants of economic universities) / K. I. Kurbakov, T. L. Partyka, I. I. Popov, V. P. Romanov. M.: Exam, 2004.
9.Partyka G.L., Popov I.I. Computing technology: a tutorial. - M.: FORUM: INFRA-M, 2007.
10. Smirnov Yu. P. History computer science: Formation and development: textbook. allowance. Publishing house Chuvash, un-ta, 2004.
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Published: 06 March 2020External testing SSDdriveVerbatimStore " n" goUSB 3.1 GEN1 with a capacity of 240 gigabytes (53231).
Introduction
The recent trend towards replacing classic hard drives SSD storage continues to gain momentum. They have already taken root not only in PCs and laptops, but also in cases of portable storage devices.
Flash drive testing VerbatimKeypadSecurityUSB 3.0
Introduction
Continuing the topic of secure data storage, we would like to introduce you to a very interesting and original product -VerbatimKeypadSecurityUSB 3.0.
Portable hard drive testing VerbatimFingerprintsecurewith USB 3.0 interface, dual protection technology, 1TB capacity.
Introduction
Imagine a very real situation - you need to transfer large files to colleagues or friends, but you cannot do it yourself. But you can ask your friends to bring them a portable hard drive with the necessary information. But you don't want the information written on it to fall into the wrong hands. How to be in this case?
Testing 64 GB USB Drives VerbatimToughMAX and Pin Stripe.
Introduction
USB flash drives have long and firmly entered our lives and the demand for them is constantly growing. It is already difficult to imagine how we used to do without these compact, capacious and convenient storage media.
External testing SSDdriveVerbatimVx500 USB 3.1 Gen 2 240 GB (model 47442).
Introduction
The topic of portable storage drives is always of great interest. Moreover, the requirements for these devices are constantly growing not only in terms of data volume, but also in terms of write / read speed.
One in two!
Combo Flash Drive Testing VerbatimStore " n" goLightningUSB 3.0 with Lightning and USB 3.0 interfaces.
Introduction
Reviewing the company's product range verbatim, we drew attention to a very interesting flash drive from the familyStore " n" go. The fact is that, thanks to the presence of ports Lightning And USB 3.0 can work with most popular computers, smartphones and tablets.
We have taken this product to the test with great interest. And our review of the workVerbatimStore " n" goLightningUSB 3.0 read below.
Durability, reliability and quality!
microSD testing XCflash cards Verbatim Pro U3 16GB to work with 4 Kvideo.
Introduction
We have written more than once that modern gadgets in our life they occupy a very important place, and most of the necessary information we store on them. Therefore, the choice of media that we use in them should be approached responsibly. After all, it is to them that we entrust important personal information, which will be very disappointing to lose.
Considering this, our next test of data storage devices we decided to dedicate microSD XCmemory card designed for portable devices Verbatim Pro U3.
The manufacturer positions the flash drive as a device for storing media data up to format 4 K.
Well, read about the work of the carrier below.
Gigabytes to go!
Store "n" Go USB 3.0 500 GB Portable Hard Drive Test (Model 53196).
Introduction
The topic of portable hard drives, judging by the letters of our readers, is very popular and in demand. Therefore, we decided to continue our acquaintance with a series of discs Store "n" Go fromVerbatim. After all, the drives of this series are positioned by the company as high-speed and very reliable devices at an affordable price.
Our series of publications continues with a story about the operation of a hard drive Store "n" Go (Model 53196) with port USB 3.0 with a capacity of 500 gigabytes.
Universal "soldier" of the media front!
Verbatim Pro U3 32GB SDHC Card testing.
Introduction
We have repeatedly tested various flash drives with USB port, and now our "tenacious paws" got to the memory cards. We decided to test how their characteristics correspond to the declared ones.
And started with Verbatim Pro U3 32GB SDHC Card. We chose this model based on its high speed characteristics, orientation to work with 4 K video and of course for a very reasonable price.
Introduction
We continue a series of articles about testing products purchased from Uncle Alik (Aliexpress).
In this review, we will share the test results with you SSD drive Londisk familiesAuroravolume 960 GB.
The fact is that we needed to upgrade one of the laptops, but the memory and processor in it were already set to the maximum, and the performance was not enough. And we decided to replace the standard "hard" speed SSD.
As always, having examined the prices of Moscow stores, we decided to save a little, the price was very high for SSD the amount we need. And again our path lay to Uncle Alik. On the site, we chose for a long time from a rich assortment SSD the most suitable option and settled on Londisk Aurora960 GB.
Well, read the results of our “running in” of the device below.
Testing compact external Blu-ray recorder Verbatim with USB 3.0 interface.
Introduction
If you look at the packaging of modern laptops, you can see one very interesting trend. Namely, more and more manufacturers are trying not to install optical drives in them. And this applies not only to light and compact ultrabooks, even ordinary laptops are increasingly being sold without them.
But sometimes the user needs to create an archive copy of his data for long-term storage and preferably with a guarantee against damage. Previously, in this case, we used CD or DVD carriers. But their capacities by modern standards are very small. Of course, you can use a flash drive or external hard drive but they sometimes fail.
The easiest way out of this situation is to buy an external recorder. Well, given the growth in the volume of user data, the external Blu-ray drive is perfect for this.
Who is interested to know our opinion about the work Verbatim Blu-ray Recorder with USB 3.0 Interface read the review below.
External data storage devices appeared a very long time ago, in fact, at the dawn of the computer era, all data storage devices were external. This approach to connectivity was largely due to the storage technology used at the time and the general level of development of the semiconductor industry. However, over time, data drives moved inside nice and compact cases. personal computers(PC).
Progress is progress, miniaturization reaches new and new heights. However, for some tasks there is still a need for external data storage devices. For example: a designer who has to transfer large files to a customer or needs to work with this material at home. Again, it may be necessary absolute protection his information from access by strangers: he turned off the disk and took it with him - what is called absolute protection :).
Below I will consider the main ways to connect external data drives and their characteristic features - a kind of historical tour.
True, for this method of connection it was required that both machines had a SCSI interface, and at that time this pleasure cost a lot of money. However, for some tasks, this ability to quickly transfer and connect storage media of large amounts of data was simply invaluable. As an interface, SCSI had and still has a lot of possibilities, but they are all locked into a rigid framework of high price. However, this method of connection has other disadvantages. Perhaps the main ones can be considered the use of thick and bulky 50-core connecting cables and the low prevalence of the SCSI interface. The photo shows SCSI and USB interface cables for comparison.
The IDE interface, which began its triumphal march on the PC market a little later, was very primitive in its capabilities, but had a huge advantage over SCSI - it was very cheap. But the old rule that “cheap is not good” has not stopped working. The wider the IDE interface spread to the PC, the more acute the need arose to implement such functions that SCSI already had, including the ability to use the IDE to connect external media data. The industry took the shortcut to solve this problem. This, as you guessed, is about the so-called Mobile Rack devices. This is a primitive basket that houses a hard drive and a socket, which is usually installed in a 5 inch slot on the front of the PC.
This whole design allows you to connect / disconnect the hard drive without disassembling the computer. To call such a method of connecting data drives "external" the language does not turn, however, without fish and cancer - a fish, it turns out, although not very convenient, but cheap. Moreover, for a very narrow range of tasks, this method is almost ideal. Over time, the possibilities provided by new operating systems even made it possible to implement the primitive ability to hot-swap IDE drives. But too frequent cases of disk failure with such a connection sharply limit both the scope of this method and the number of users who want to risk their hardware. In addition, Mobile Rack baskets made by different companies were often physically incompatible with the jacks due to the non-standard location of the connectors. However, the Mobile Rack connection method is still alive and well.
But let's go back a little. The possibilities that the primitive Mobile Rack provided, of course, could not fully satisfy users, and the computer industry once again launched the process of evolution.
In the following, I will mainly use IDE device examples, since it is more common. But everything that will be said about the IDE can just as well be said about SCSI, since the ideology remains the same regardless of the interface.
This approach - using the LPT interface - was certainly not ideal, but it worked nonetheless. So, what the user could get in the end.
Well, the first pancake always turns out lumpy. Nevertheless, it is important for us that the industry first applied bridge technology in practice. This was the first step in the development of a whole class of similar devices.
However, as time went on, the capacity of hard drives grew, and the amount of data grew. The speed provided by the LPT interface has become sorely lacking. The industry began to look for new ways to connect faster and more capacious drives.
The idea of connecting devices through bridges began to develop in new directions. By that time, almost all more or less modern computers were equipped with such a peripheral data transfer bus as USB. Although USB was the most common bus, it also turned out to be the most unclaimed at that time. A rather promising development, integrated by INTEL into its chipsets and therefore practically worthless, it was present on many motherboards, but the lack of devices that could work with this bus turned it into a beautiful toy. Now the time has come. In fact, USB was developed as a peripheral bus for connecting computer peripherals outside the machine case according to the plug "n" play standard. The old man LPT simply could not resist such pressure. So, what could users get when switching from an LPT-IDE bridge to a USB-IDE bridge.
It was impossible to pass by such an opportunity to use USB, and users received a whole range of IDE devices capable of working via USB 1.1. Here are some examples.
USB-IDE bridge board - what is called a do-it-yourself constructor. The user can, if desired, easily convert any external storage enclosure he has.
External case for 3-inch hard drive.
External case for 2-inch hard disk, with some models of hard disks, even operation without external power is possible.
A small lyrical digression. Despite the fact that the methods of connecting drives using a bare interface and using a bridge have fundamental differences, the market is a market, and if there are unoccupied niches in it, then they should be taken. Apparently, guided by such motives, some companies have developed such curious combi devices that can work in different guises.
Allows you to work in two modes: as a universal Mobile Rack for computer devices, and as an external device connected with using USB bridge. In the first case, you have the ability to quickly remove the storage media from the computer without disassembling it, and in the second case, you can easily connect the removed media to any computer that does not have a Mobile Rack slot, but has a USB bus.
Again, a small example. Here is the case for the 2" hard drive.
However, unlike USB, the user does not have to puzzle over how to find a suitable hard drive that will work without additional food. Power is taken directly from the bus (1.25A 12V = 15W), so absolutely any hard drive will do.
However, progress does not stand still, and clouds hang over FireWire in the form of USB 2.0. Possessing somewhat better characteristics, it is able to become its serious competitor. The main trump cards in the fight were to be an increase in speed from 10 MBit / s to 480 MBit / s and support for all older USB 1.1 devices. True, when introducing USB 2.0 to the market, some bewilderment is caused by the policy by Intel. Previously, the corporation actively promoted this bus, but, contrary to the expectations of users, did not integrate it into their latest i845D and i850 chipsets. Why this did not happen remains a mystery. However, there is already everything that is needed for the widespread adoption of USB 2.0 in the PC market. Firstly, the market is more than provided with chips to create expansion cards for USB support 2.0, and secondly, external storage devices that use USB 2.0-IDE bridges are actively moving into the market.
Here, for example, is a bridge on a chip from In-System. It is designed in such a way that it can very easily replace the previous generation bridge (photo a little higher in the text). And that's not all, the company's pricing policy is such that the cost of a USB 2.0 bridge is almost equal to the cost of the previous USB 1.1 model.
The market is a market, and if there is a demand, then everyone who can will try to get into this niche in the market. Therefore, it is not surprising that a natural process of competition was observed in this segment of the market. As usual, competing firms presented their products one after another. This is where we get some differences in transmission speed for practically similar products, but using bridges from different companies.
For USB 1.1, this difference was not so fatal due to the low transfer rate. The values of the maximum possible transmission speed, as a rule, ranged from 750-950 Kb/s. However, a 20% difference looks quite large.
Much more interesting was the situation on the market for high-speed IDE-FireWire bridges. Here the maximum speed could differ several times. Moreover, I observed such a difference in devices of the same company, assembled on different chips of FireWire-IDE bridges. Curiously, both chips were from the same manufacturer. Below you can take a look at the comparison results.
Chip Oxford semi. OXFW910
Chip Oxford semi. OXFW911
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Well, is the difference impressive? I can understand those who, for example, need to connect a CD-RW recorder through a similar bridge. By and large, they will not give a damn about speed, but what about those who want to connect a modern high-speed hard drive? So, as they say, be careful when choosing such a device for yourself. Below I will give the test data of some of the most commonly used chips on the basis of which IDE-FireWire bridges are built. Data obtained from Skymaster. This company is engaged in the production of all kinds of USB and FireWire devices. An IBM DTLA-307020 hard disk was used as a test device; testing was carried out under OS Windows 2000.
Unfortunately, there is no way to compare at least two USB 2.0-IDE bridges, since at the moment only In-System supplies such devices to the market. But recently, two more large companies - NEC and ALI - have announced similar devices, so let's see what they get, and in the future we will try to compare them.
In one place you have FireWire, in another you only have USB, and you want, for example, to bring a friend a couple of new films in DVD format, but rewritten to a hard drive. However, you have a FireWire drive, and your friend only has USB 1.1, well, he shouldn’t get a FireWire controller for this. Well, the controller can and should be brought in, especially since peripheral manufacturers have long been hinting at the need for all widely used peripheral buses in every computer. Just take a look at this universal hub, isn't it cute and practical?
But this card can make you happy with two high-speed buses at once - USB 2.0 and FireWire.
Well, versatility is a sacred thing, - the manufacturers decided and, without thinking twice, they set about developing bridges with combined interfaces. In principle, the main difficulty is to compactly place all the necessary components on the bridge board and try at the same time so that the cost of such a device does not turn out to be excessively high. The first bird was such a FireWire / USB1.1 bridge - IDE.
And this is just the beginning, as the FireWire/USB2.0 -IDE versions are ready and will soon be put into production. Here the user can afford to forget about the compatibility of his external drive with computers, since the computer has some kind of peripheral bus for sure :).
This year has been marked final version Serial ATA interface. And although for now it is intended only to replace the outdated IDE, it already has the manners of Napoleon. Judge for yourself, this interface is almost identical in its functions to both a FireWire device and USB 2.0, but at the same time even faster. The data transfer rate of Serial ATA can reach 150 Mb/s. Of course, it will be some time before it hits the market in all its glory. Although it is currently positioned exclusively as internal interface, but, nevertheless, has all the makings of an interface for connecting external devices. See for yourself, the interface uses a star topology to connect devices. So you can bring out one or two connectors for connecting external devices without any problems, and at the same time the devices will function similarly to internal ones. The maximum cable length is 1 meter - this is also quite enough to connect most external devices.
The cable consists of two pairs of data wires and three ground wires, so the cable is very compact and convenient. Of course, the future will show whether this interface will invade the external storage market or not, but this possibility must be kept in mind.
HDD hard drive. This is the main device for long-term storage of large amounts of data and programs. It is a group of coaxial discs with a magnetic coating and rotating at high speed. The main parameters of a hard disk include capacity, performance, and average access time. The determining interval of time required to find the desired data depends on the speed of rotation of the disk.
FDD floppy disk drive. This is a device for using 3.5-inch floppy disks (produced since 1980), with a capacity of 1440 KB.
CD-ROM (Compact Disk-Read-Only Memory) drive. It is a CD-based read-only storage device. The principle of operation is to read numerical data using a laser beam reflected from the surface of the disk.
ZIP driver. Designed to use disks with a capacity of 100, 250, 750 MB and above. Produced by Iomega internally (connects to the hard disk controller motherboard) and external version (connects to a standard parallel port, which negatively affects the speed of data exchange). The main disadvantage of ZIP drives is their lack of compatibility with standard 3.5-inch floppy disks. Sony HiFD devices, both special 200 MB media and conventional floppy disks, have this compatibility, but at an increased cost.
Drives JAZ. Produced by Iomega, their characteristics are close to hard drives, but unlike them, they are replaceable. Depending on the drive model, you can store 1 or 2 GB of data.
Streamers. These are magnetic tape drives for reading information from a hard disk onto the magnetic tape of an audio or video recorder. The disadvantages of streamers include low performance and low reliability. The capacity of magnetic cassettes (cartridges) for streamers reaches several tens of gigabytes.
Flash drives. These are modern storage devices based on non-volatile flash memory. The device has a minimal size and can be hot plugged into a USB connector, after which it is recognized as a hard drive, and does not require driver installation. Flash drives can range in size from 32 MB to 1 GB and are held back by relatively high prices.
RAM(RAM - Random Access Memory, random access memory). It is located on the motherboard and looks like special small boards (modules) inserted into special slots.
ROM chip and BIOS system. IN the moment the computer is turned on random access memory(OP) there are no data or programs, since RAM cannot store anything without recharging cells for more than hundredths of a second, but the processor needs commands, including at the first moment after switching on. Immediately after switching on, the start address is set on the address bus of the processor, which points to the ROM. A set of programs located in ROM forms the BIOS (Basic Input Output System) basic input-output system, the main purpose of which is to check the composition and performance computer system and provide interaction with the keyboard, monitor, hard drive and drives. The ROM chip is capable of storing information for a long time, even when the computer is turned off. The programs located on the ROM are called "wired" - they are written there at the stage of manufacturing the microcircuit. The programs included in the BIOS allow you to monitor diagnostic messages accompanying the start of the computer.
Non-volatile CMOS memory. Especially in order to store information about the hardware of a particular computer, the motherboard has a non-volatile memory chip called CMOS. It differs from RAM in that its contents are not erased when the computer is turned off, and from ROM in that data can be entered and changed using the Setup program, in accordance with what equipment is included in the system. This microcircuit is constantly powered by a small battery located on the motherboard, the charge of which is enough to ensure that the microcircuit does not lose data, even if the computer is not turned on for several years.
The CMOS chip stores data about floppy and hard disks, about the processor, about some other devices on the motherboard. The fact that the computer clearly keeps track of the time and calendar (even when turned off) is also due to the fact that the system clock is constantly stored (and changed) in CMOS.
Thus, the programs written in the BIOS read data on the composition of the computer hardware from the CMOS chip, after which they can access the hard disk, and, if necessary, the flexible one, and transfer control to those programs that are written there.
Video card (video adapter). Together with the monitor, the video card forms the PC video system. During the development of the PC, all operations related to screen management were separated into a separate unit, called the video adapter, which took over the functions of the video controller, video processor and video memory.
During the existence of the PC, several standards for video adapters have changed, currently the SVGA standard is used, which provides a choice of reproduction of 16.7 million colors with the ability to randomly select a screen resolution from a standard range of values (640 x 480, 800 x 600, 1024 x 768, 1152 x 864, 1280 x 1024 dots, etc.).
Screen resolution is one of the most important parameters of the video subsystem. The higher the resolution, the more information can be displayed on the monitor screen, but the smaller the size of each individual dot and, accordingly, the visible size of image elements. For a monitor of any dimension, there is an optimal screen resolution that the video adapter must provide.
Color resolution or color depth determines the number of different shades that a single point on the screen can take on. The minimum requirement for color depth today is 256 colors, although most programs require at least 65K colors (High Color mode), most comfortable work achieved at a color depth of 16.7 million colors (True Color mode). The maximum possible color resolution depends on the amount of video memory installed and the screen resolution.
Video acceleration is one of the properties of a video adapter, which consists in the fact that part of the imaging operations can take place without performing mathematical calculations in the main computer processor, but purely by hardware - due to data conversion in the video accelerator chips. There are two types of video accelerators - flat 2D and three-dimensional 3D graphics accelerators. All modern video cards have both 2D and 3D acceleration features.
A TV tuner is a device for receiving data from a TV or VCR on a monitor screen.
Peripherals. Computer peripherals include:
Input devices
Image input devices include scanners. Consider the main types of scanners.
Flatbed scanners. Designed for input graphic information from transparent or opaque sheet material. The principle of operation is that a beam of light reflected from the surface of a material is fixed by special elements called charge-coupled devices (CCDs).
Typically, CCD elements are structurally designed in the form of a ruler located along the width of the source material. The movement of the ruler relative to the sheet of paper is performed by mechanically pulling the ruler while the sheet is stationary or by pulling the sheet while the ruler is stationary.
Main consumer parameters of flatbed scanners:
hand scanners. These scanners work in the same way as flatbed scanners, but they have low resolution and poor quality. Resolution - 150-300 dpi.
drum scanners. Devices for scanning original images that have high quality, but insufficient linear dimensions, such as photo negatives, slides. The source material is fixed on the cylindrical surface of the drum, which rotates at high speed and provides a resolution of 2400-5000 dpi due to the use of photomultipliers rather than CCDs.
Form scanners. Input devices for standard forms filled in mechanically or by hand, for example in population censuses, in the processing of election results and the analysis of data questionnaires.
Barcode scanners. To enter data encoded as a barcode (retail).
Graphic tablets (digitizers). Devices for inputting artistic graphic information allow you to create screen images with the usual methods: pencil, pen and brush. For artists, illustrators.
Digital cameras. Devices that perceive graphical data using charge-coupled devices combined in a rectangular matrix. The best consumer models have 2-4 million CCD cells and accordingly provide a resolution of up to 1600 x 1200 dpi and higher. Professional models have even higher resolution.
Data output devices
Dot matrix printers. The data is printed on paper in the form of an imprint formed by the impact of cylindrical rods (needles) through the ink ribbon. 9- and 24-pin dot matrix printers are common.
Inkjet printers. The image is formed from the spots formed when drops of dye hit the paper. Dye droplets are ejected under pressure, which develops in the print head due to vaporization. The print quality depends on the shape of the drop and its size, as well as on the nature of the absorption of liquid dye by the paper surface. To the virtues inkjet printers can be attributed to a relatively small number of moving mechanical parts and, accordingly, the simplicity and reliability of the mechanical part of the device, relatively low cost.
LED printers. The light source in these printers is a line of LEDs. Since this ruler is located across the entire width of the printed page, there is no need for a mechanism for forming a horizontal scan, and the whole design is simpler, more reliable and cheaper. A typical print resolution for LED printers is around 600 dpi.
Laser printers. They provide high quality prints and feature fast print speeds, measured in pages per minute. The main parameters of laser printers include:
Professional models provide print resolution
from 1800 dpi and above, middle class - up to 600 dpi.
Communication devices
Modems. Designed to exchange information between remote computers via communication channels. In this case, the communication channel is understood as physical lines: wired, fiber optic, cable, radio frequency, how they are used (switched and dedicated) and how data is transmitted (digital or analog signals). Depending on the type of communication channel, receiving and transmitting devices are divided into radio modems, cable modems, etc. The most widely used are modems oriented to connecting to dial-up telephone communication channels.
The digital data coming to the modem from the computer is converted in it by modulation (in amplitude, frequency and phase) in accordance with the chosen standard (protocol) and sent to the telephone line. A receiver modem that understands this protocol performs inverse conversion (demodulation) and sends the recovered digital data to its computer.
MicroSD cards have recently been produced with the largest capacity and fastest speed since their introduction. The new 128 GB cards have shown that over a thousandfold increase in storage density has occurred over the past decade, and the fastest of these microSD cards can now compete with other high speed wireless networking attributes.
The SD Association was formed by application developers and manufacturers of microSD cards and components for them. The organization sets the technology standards and sets the direction for the microSD industry. SD Association President Brian Kumagai spoke about some of the latest trends in technology that will allow microSD to remain viable in the future, remaining in demand storage
Six months ago, these pages would have featured large text on 240 and 480 GB models, but in current financial conditions, we settled on 120 GB options. Many people think that one rule should be followed in this sector - take it cheaper and don't bother - but not everything is so simple, the market for budget solid state drives is very tricky. 
Under a well-known brand and a proven series, a sample of the previous generation on an old controller and memory type may well be hiding. In order to avoid such situations, we studied five drives in detail: Plextor M6S, OCZ Arc 100, Kingston HyperX 3K, SanDisk Ultra Plus and ADATA XPG SX910.
Let's say right away that we will not deal with the description of the configuration and appearance of the SSD in the course of the article. All participants are thin metal rectangles, differing only in different
If the laptop owner does not have enough memory on the device, its volume can be increased using a SATA disk. The main difference between this method of increasing memory is that this will require a USB drive. The installation of this hard drive is simple, and if you don’t want to do it yourself, we recommend good service professional laptop repair. Now let's move on to describing the procedure for this procedure and considering the technical features. 
1. Connect the USB drive connected to the container to the laptop using a cable for the USB port.
2. For the laptop to detect SATA drive, you need to enable the settings for working with the connected drive. After all the wires are connected, you will see that the corresponding bulbs light up.
3. Turn on your PC, and while booting it, press the Delete key. The menu will be displayed BIOS settings, in which you need to select a line that displays connected devices, including HDD SATA.
4. When installing an additional disk, each operating system also requires a driver for them, however, there are also OS versions that already have drivers for the SATA disk.
For some users, the word "driver" is unfamiliar, why
This creates an obvious need for such media that can store huge amounts of data. Optical discs, which not so long ago were considered quite capacious, today cannot provide this task. Even the capacity of Blu-ray discs is no longer enough. 
To record any information on optical disc, it is necessary to burn each of its bits with a laser beam on its surface. Later, this pattern, consisting of small dots, is read by a special device and converted into raw data.
The size of these dots just determines the capacity of the disk. But it cannot be reduced to infinity, since the diffraction limit that sets the width of the light beam is one second of the radiation wavelength. This results in the diameter
Campaign, in five or eight years it will be possible to do without hard in system unit, stuffing it with a couple of fat SSDs for storing all sorts of different things. At least a terabyte will be enough for me to save all important information and another terabyte will go under any multimedia content, the life of which does not exceed a couple of months. I will entrust everything else to the encrypted storage under the table (I think by that time they will release NAS on slow, but reliable flash drives). 
A kind of spindleless future with the possibility of dynamic overloads of several hundred Gs. A solid state from ADATA prompted me to such spatial fabrications. Quite suddenly, this 256 GB drive was based not on some SandForce (I know, I know, they can be cooked correctly, but I dislike them because of the dreary past), but on Marvell 88SS9189. At the same time, such a thing can be found in retail for less than 5,000 rubles! Yes, petrofan is a considerable amount, you can take three terabytes for it
When I came to test the Seagate Wireless Plus external hard drive, I thought that this device is brilliant and able to change the world, break stereotypes and bring humanity one step closer to a great bright future. In fact, this electronic device is one big facepalm. I already hear a lot of selective swearing and see rotten vegetables on the way. It's Seagate, how come they couldn't! 
Outwardly, the disk looks solid: it is clear that it was sharpened under the ilith. At first I was seduced, though a rogue at heart. The build quality is at its best, it does not creak, does not break, does not fall off, solid impact-resistant plastic. main feature Wireless Plus is not in volume (only 1 TB, which is not wow by modern standards) and USB 3.0, but in the fact that it can work without wires. At all. This is his trump card, his most impressive difference from all
