Dell's official community page again. recalled. the existence of format hard drives Advanced Format, who delivered the many problems.
In general, Advanced Format ( as. write. by hwp. ru) - is ... As you know, the logical structure of the hard drive includes a number of cylinders and sectors, which, like a lattice, twisted around the axis of the disk platter surface is divided into so-called clusters that span multiple sectors. In these clusters, data is written to disk. The standard size of the sector, adopted so far is 512 bytes, but everything has a limit. Back in 1998 the idea to increase the size of the sector, and in 2007, Industrial Organization IDEMA LDS-Committee (International Disk Drive Equipment and Materials Association) « legalized » the idea of the release of the document «Hard Disk Drive Long Data Sector White Paper», which were described by all . A little later, Samsung has released a couple of hard drives, small form factor 2. 5 inch - models Spinpoint M7E and portable S1 Mini - which was a large cluster technology is applied. Western Digital has gone a step further by launching the production of a whole range of drive technology, which is called Advanced Format. The advantage of the new layout not only provides increased drive for recording data, but also drive increased productivity through more optimized data placement on disk.
The increase achieved by the fact that instead of the eight sectors of 512 bytes sector entered a 4 KB. As a result, the structure of the drive just disappear ... That is, as you know, reducing the number of sectors makes it possible to increase the working space of the disc - precisely because it reduces the amount of official information, it is true in the area of ECC type structure Advanced Format somewhat extended (compared to the short sector), but not much. You may ask, why is all this necessary? . Therefore an increase in the sector, coupled with a wider area of ECC provides benefits not only in the speed of data access, but also achieves a smaller number of errors in reading. An increase in the work area for storing data, we have said above, we can only specify that the increase from the usual structure of the disk is no more than 10-12%, but it is still quite an impressive size, to talk about winning in the amount of earnest. Finally, the increasing size of the introduction of new sectors of the areal density and achieves a linear increase in reading speed, not to mention the optimization of the search.
However, there are also disadvantages: this case is not only the increased load on the drive electronics, but also a far more important thing: the fact that from the very beginning of computer age, all components of IBM-compatible PCs are designed to work with in 512 . This operating system, and motherboards, and controllers. For some reason, Microsoft in its operating systems used for partitioning the indentation, reserving the first 63 sectors on the disk when you install the OS. Mindful of the possible. incompatible with such systems. Engineers of Western Digital have chosen this format for the new drive: HDD is physically marked sectors of 4 KB, but the drive system of the Official Reports that can work with the sectors of 512 bytes. That is great physical sectors on the disk have eight 512-byte logical sectors - the same 4 kb.
Thus, the new drives above the 63rd sector is flat on the eighth of the eighth logical physical sector, which leads to a mismatch cluster file system sector, marked on the hard disk. It would seem to align enough to shift the logical structure of the drive on a single sector, but in this case, the entire disk should be marked by a section. In the case of several sections of the situation is seriously complicated by the. Thus, if the increased demands on the performance of the electronic part of the disk is relatively easy to fight - the same WD drives are equipped with dual-core has long been the controller - is the second factor is more complicated:. The first step in the universal and inexorable way to the LDS (Long Data Sector), Microsoft has already done - its latest operating system Windows Vista and Windows 7 already support disks with large sectors - using the new OS, you can not worry about compatibility with new discs. Also, support for Advanced Format can be found in the latest RAID- controllers. Yes, and BIOS-level motherboards are gradually introduced support for LDS. However, to say absolutely that it is your system is 100% support Advanced Format is still too early. Of course, the new computer will be free of compatibility issues, but that older PCs can give a nasty surprise. That is to use a disk sector with an increased need to install the Windows Vista or Windows 7 as a minimum, and preferably have a modern motherboard or RAID- controller with the latest firmware version. However, the use of old hardware and operating systems is possible because the drive manufacturers have prepared options for ensuring the compatibility of Windows XP and below on the new disk. As a rule, it can be done in two ways: the new firmware and software of a higher level, as well as through physical rearrangement of jumpers at the end of disc-based media.
Nevertheless, specialists Dell, which also produce. storage. the new format, and are forced to ensure compatibility of their computer, server and mobile systems with third-party products, noted that the difficulties with the use of Advanced Format is still regularly occur.
One of them - it's arbitrary methods to identify AF- drive. For example, WD marks of their letters EARS, AARS and BPVT. Other companies set the logo proposed by the developer of the format - IDEMA:.
The second major issue - it's method of data migration due to the change of the operating system: AF- disk -mode of the traditional media, if you update your working OS can significantly lose productivity due to the shift of sectors.
And finally the Dell once again focused attention on the need to ' dance with tambourines ' when working with older operating systems.
Source: hwp, dell.
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